From 9e0d925f9563bf12d8b3a95e1a238b6eaac1819f Mon Sep 17 00:00:00 2001
From: John Richmond <5629+jr@users.noreply.github.com>
Date: Mon, 29 Sep 2025 13:09:26 -0700
Subject: [PATCH 1/9] Check for a few more esoteric subshell patterns

---
 .../__tests__/command-validation.spec.ts      | 36 +++++++++++++++++++
 webview-ui/src/utils/command-validation.ts    |  9 ++++-
 2 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/webview-ui/src/utils/__tests__/command-validation.spec.ts b/webview-ui/src/utils/__tests__/command-validation.spec.ts
index e87bae07e5..58edc86723 100644
--- a/webview-ui/src/utils/__tests__/command-validation.spec.ts
+++ b/webview-ui/src/utils/__tests__/command-validation.spec.ts
@@ -313,6 +313,30 @@ ls -la || echo "Failed"`
 			expect(containsDangerousSubstitution("rm *(e:sudo apt install malware:)")).toBe(true)
 		})
 
+		it('detects bash $"..." string interpolation with command substitution', () => {
+			// The exact example from the issue
+			expect(containsDangerousSubstitution('echo $"test$(whoami)"')).toBe(true)
+
+			// Various forms of command substitution inside $"..."
+			expect(containsDangerousSubstitution('echo $"Hello $(date)"')).toBe(true)
+			expect(containsDangerousSubstitution('echo $"User: `whoami`"')).toBe(true)
+			expect(containsDangerousSubstitution('echo $"test`pwd`"')).toBe(true)
+
+			// Multiple command substitutions
+			expect(containsDangerousSubstitution('echo $"$(date) - $(whoami)"')).toBe(true)
+			expect(containsDangerousSubstitution('echo $"User: `whoami` in `pwd`"')).toBe(true)
+
+			// Command substitution at different positions
+			expect(containsDangerousSubstitution('echo $"$(whoami) is the user"')).toBe(true)
+			expect(containsDangerousSubstitution('echo $"The user is $(whoami)"')).toBe(true)
+			expect(containsDangerousSubstitution('echo $"Current $(date) time"')).toBe(true)
+
+			// Complex command substitutions
+			expect(containsDangerousSubstitution('echo $"Files: $(ls -la)"')).toBe(true)
+			expect(containsDangerousSubstitution('echo $"Process: $(ps aux | grep node)"')).toBe(true)
+			expect(containsDangerousSubstitution('echo $"Result: `rm -rf /`"')).toBe(true)
+		})
+
 		it("does NOT flag safe parameter expansions", () => {
 			// Regular parameter expansions without dangerous operators
 			expect(containsDangerousSubstitution("echo ${var}")).toBe(false)
@@ -351,6 +375,15 @@ ls -la || echo "Failed"`
 			expect(containsDangerousSubstitution("rm *.txt")).toBe(false)
 			expect(containsDangerousSubstitution("cat ?(foo|bar)")).toBe(false)
 			expect(containsDangerousSubstitution("echo *(^/)")).toBe(false) // Safe glob qualifier (not e:)
+
+			// Safe $"..." strings without command substitution
+			expect(containsDangerousSubstitution('echo $"Hello World"')).toBe(false)
+			expect(containsDangerousSubstitution('echo $"This is a test"')).toBe(false)
+			expect(containsDangerousSubstitution('echo $"User: $USER"')).toBe(false) // Variable expansion is safe
+			expect(containsDangerousSubstitution('echo $"Path: ${PATH}"')).toBe(false) // Variable expansion is safe
+			expect(containsDangerousSubstitution('echo $"Count: $count"')).toBe(false)
+			expect(containsDangerousSubstitution('echo $"Translated string with no substitution"')).toBe(false)
+			expect(containsDangerousSubstitution('echo $""')).toBe(false) // Empty translated string
 		})
 
 		it("handles complex combinations of dangerous patterns", () => {
@@ -379,6 +412,9 @@ ls -la || echo "Failed"`
 
 			// The zsh glob qualifier exploit
 			expect(containsDangerousSubstitution("ls *(e:whoami:)")).toBe(true)
+
+			// The bash $"..." string interpolation exploit
+			expect(containsDangerousSubstitution('echo $"test$(whoami)"')).toBe(true)
 		})
 	})
 })
diff --git a/webview-ui/src/utils/command-validation.ts b/webview-ui/src/utils/command-validation.ts
index 572ca32bad..3a35b02849 100644
--- a/webview-ui/src/utils/command-validation.ts
+++ b/webview-ui/src/utils/command-validation.ts
@@ -73,6 +73,7 @@ type ShellToken = string | { op: string } | { command: string }
  * - <<<$(...) or <<<`...` - Here-strings with command substitution
  * - =(...) - Zsh process substitution that executes commands
  * - *(e:...:) or similar - Zsh glob qualifiers with code execution
+ * - $"..." with command substitution - Bash translated strings with embedded command execution
  *
  * @param source - The command string to analyze
  * @returns true if dangerous substitution patterns are detected, false otherwise
@@ -111,6 +112,11 @@ export function containsDangerousSubstitution(source: string): boolean {
 	// This regex matches patterns like *(e:...:), ?(e:...:), +(e:...:), @(e:...:), !(e:...:)
 	const zshGlobQualifier = /[*?+@!]\(e:[^:]+:\)/.test(source)
 
+	// Check for $"..." string interpolation with command substitution
+	// $"..." is a bash feature for translated strings that allows command substitution inside
+	// e.g., echo $"test$(whoami)" or echo $"test`pwd`"
+	const bashTranslatedStringWithSubstitution = /\$"[^"]*(\$\(|`)[^"]*"/.test(source)
+
 	// Return true if any dangerous pattern is detected
 	return (
 		dangerousParameterExpansion ||
@@ -118,7 +124,8 @@ export function containsDangerousSubstitution(source: string): boolean {
 		indirectExpansion ||
 		hereStringWithSubstitution ||
 		zshProcessSubstitution ||
-		zshGlobQualifier
+		zshGlobQualifier ||
+		bashTranslatedStringWithSubstitution
 	)
 }
 

From 952d8af3e8f67d56c8170d25d69eecbe4f41d996 Mon Sep 17 00:00:00 2001
From: John Richmond <5629+jr@users.noreply.github.com>
Date: Mon, 29 Sep 2025 15:32:40 -0700
Subject: [PATCH 2/9] Better handle nested backticks

---
 .../utils/__tests__/command-validation.spec.ts    | 11 +++++++++++
 webview-ui/src/utils/command-validation.ts        | 15 ++++++++++++---
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/webview-ui/src/utils/__tests__/command-validation.spec.ts b/webview-ui/src/utils/__tests__/command-validation.spec.ts
index 58edc86723..2427fc64b2 100644
--- a/webview-ui/src/utils/__tests__/command-validation.spec.ts
+++ b/webview-ui/src/utils/__tests__/command-validation.spec.ts
@@ -43,6 +43,12 @@ describe("Command Validation", () => {
 			expect(parseCommand("diff <(sort f1) <(sort f2)")).toEqual(["diff", "sort f1", "sort f2"])
 		})
 
+		it("handles nested backticks with escaped inner backticks", () => {
+			const cmd = "echo `echo \\`whoami\\``"
+			// Should surface both the outer echo and the inner whoami as separate sub-commands
+			expect(parseCommand(cmd)).toEqual(["echo", "echo", "whoami"])
+		})
+
 		it("handles empty and whitespace input", () => {
 			expect(parseCommand("")).toEqual([])
 			expect(parseCommand("	")).toEqual([])
@@ -1075,6 +1081,11 @@ describe("Unified Command Decision Functions", () => {
 
 			// Main command with denied prefix should also be auto-denied
 			expect(getCommandDecision("npm test $(echo hello)", allowedCommands, deniedCommands)).toBe("auto_deny")
+
+			// Nested backticks with escaped inner backticks should not be auto-approved when inner command isn't allowed
+			expect(getCommandDecision("echo `echo \\`whoami\\``", ["echo"], [])).toBe("ask_user")
+			// And should be auto-denied when inner command is on the denylist
+			expect(getCommandDecision("echo `echo \\`whoami\\``", ["echo"], ["whoami"])).toBe("auto_deny")
 		})
 
 		it("properly validates subshell commands when no denylist is present", () => {
diff --git a/webview-ui/src/utils/command-validation.ts b/webview-ui/src/utils/command-validation.ts
index 3a35b02849..a4c4f8c107 100644
--- a/webview-ui/src/utils/command-validation.ts
+++ b/webview-ui/src/utils/command-validation.ts
@@ -256,8 +256,10 @@ function parseCommandLine(command: string): string[] {
 			subshells.push(inner.trim())
 			return `__SUBSH_${subshells.length - 1}__`
 		})
-		.replace(/`(.*?)`/g, (_, inner) => {
-			subshells.push(inner.trim())
+		// Handle backticks with support for escaped backticks (e.g., \`)
+		.replace(/`((?:\\`|[^`])*)`/g, (_, inner) => {
+			const unescaped = inner.replace(/\\`/g, "`").trim()
+			subshells.push(unescaped)
 			return `__SUBSH_${subshells.length - 1}__`
 		})
 
@@ -318,7 +320,14 @@ function parseCommandLine(command: string): string[] {
 					commands.push(currentCommand.join(" "))
 					currentCommand = []
 				}
-				commands.push(subshells[parseInt(subshellMatch[1])])
+				// Expand subshell into its constituent commands to catch nested substitutions
+				const subshellContent = subshells[parseInt(subshellMatch[1])]
+				const expanded = parseCommand(subshellContent)
+				if (expanded.length > 0) {
+					commands.push(...expanded)
+				} else if (subshellContent.trim()) {
+					commands.push(subshellContent.trim())
+				}
 			} else {
 				currentCommand.push(token)
 			}

From 63b171b1a2f75563c4f872fde03470aad9002445 Mon Sep 17 00:00:00 2001
From: John Richmond <5629+jr@users.noreply.github.com>
Date: Mon, 29 Sep 2025 15:43:28 -0700
Subject: [PATCH 3/9] More patterns

---
 .../src/utils/__tests__/command-validation.spec.ts    |  4 ++++
 webview-ui/src/utils/command-validation.ts            | 11 +++++++----
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/webview-ui/src/utils/__tests__/command-validation.spec.ts b/webview-ui/src/utils/__tests__/command-validation.spec.ts
index 2427fc64b2..6180e6d28e 100644
--- a/webview-ui/src/utils/__tests__/command-validation.spec.ts
+++ b/webview-ui/src/utils/__tests__/command-validation.spec.ts
@@ -301,6 +301,8 @@ ls -la || echo "Failed"`
 		it("detects zsh glob qualifiers with code execution (e:...:)", () => {
 			// Basic glob qualifier with command execution
 			expect(containsDangerousSubstitution("ls *(e:whoami:)")).toBe(true)
+			// Zsh extended glob with qualifier list and brace-arg: e{'whoami'} as reported
+			expect(containsDangerousSubstitution("ls *(.e{'whoami'})")).toBe(true)
 
 			// Various glob patterns with code execution
 			expect(containsDangerousSubstitution("cat ?(e:rm -rf /:)")).toBe(true)
@@ -1043,6 +1045,8 @@ describe("Unified Command Decision Functions", () => {
 				const globExploit = "ls *(e:whoami:)"
 				// Even though 'ls' might be allowed, the dangerous pattern prevents auto-approval
 				expect(getCommandDecision(globExploit, ["ls", "echo"], [])).toBe("ask_user")
+				// Zsh extended glob with qualifier list and brace-arg form
+				expect(getCommandDecision("ls *(.e{'whoami'})", ["ls", "echo"], [])).toBe("ask_user")
 
 				// Various forms should all be blocked
 				expect(getCommandDecision("cat ?(e:rm -rf /:)", ["cat"], [])).toBe("ask_user")
diff --git a/webview-ui/src/utils/command-validation.ts b/webview-ui/src/utils/command-validation.ts
index a4c4f8c107..b92aba0d36 100644
--- a/webview-ui/src/utils/command-validation.ts
+++ b/webview-ui/src/utils/command-validation.ts
@@ -107,10 +107,13 @@ export function containsDangerousSubstitution(source: string): boolean {
 	// =(...) creates a temporary file containing the output of the command, but executes it
 	const zshProcessSubstitution = /=\([^)]+\)/.test(source)
 
-	// Check for zsh glob qualifiers with code execution (e:...:)
-	// Patterns like *(e:whoami:) or ?(e:rm -rf /:) execute commands during glob expansion
-	// This regex matches patterns like *(e:...:), ?(e:...:), +(e:...:), @(e:...:), !(e:...:)
-	const zshGlobQualifier = /[*?+@!]\(e:[^:]+:\)/.test(source)
+	// Check for zsh glob qualifiers with code execution via the "e" qualifier
+	// This must detect multiple zsh forms that execute code during glob expansion:
+	// - Classic: *(e:whoami:) or ?(e:rm -rf /:) etc.
+	// - With other qualifiers: *(.e:whoami:) (dot means "plain files" plus e:...)
+	// - Brace/quoted argument forms: *(e{'whoami'}), *(.e{'whoami'}), *(e{"whoami"}), *(.e{"whoami"})
+	// Any appearance of an "e" qualifier with an argument inside a glob qualifier list is dangerous.
+	const zshGlobQualifier = /\([^)]*e\s*(?::[^:]*:|\{[^}]*\}|'[^']*'|"[^"]*")[^)]*\)/.test(source)
 
 	// Check for $"..." string interpolation with command substitution
 	// $"..." is a bash feature for translated strings that allows command substitution inside

From 3d737c66c5003824874986337c0d42933b15c15f Mon Sep 17 00:00:00 2001
From: John Richmond <5629+jr@users.noreply.github.com>
Date: Mon, 29 Sep 2025 15:51:02 -0700
Subject: [PATCH 4/9] More restrictions

---
 webview-ui/src/utils/__tests__/command-validation.spec.ts | 7 +++++++
 webview-ui/src/utils/command-validation.ts                | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/webview-ui/src/utils/__tests__/command-validation.spec.ts b/webview-ui/src/utils/__tests__/command-validation.spec.ts
index 6180e6d28e..acea548e14 100644
--- a/webview-ui/src/utils/__tests__/command-validation.spec.ts
+++ b/webview-ui/src/utils/__tests__/command-validation.spec.ts
@@ -319,6 +319,11 @@ ls -la || echo "Failed"`
 			// Glob qualifiers with complex commands
 			expect(containsDangerousSubstitution("ls *(e:open -a Calculator:)")).toBe(true)
 			expect(containsDangerousSubstitution("rm *(e:sudo apt install malware:)")).toBe(true)
+
+			// Plus-shorthand qualifier that executes a command
+			expect(containsDangerousSubstitution("ls *(+whoami)")).toBe(true)
+			expect(containsDangerousSubstitution("ls *(.+{'whoami'})")).toBe(true)
+			expect(containsDangerousSubstitution('ls *(+"whoami")')).toBe(true)
 		})
 
 		it('detects bash $"..." string interpolation with command substitution', () => {
@@ -1045,6 +1050,8 @@ describe("Unified Command Decision Functions", () => {
 				const globExploit = "ls *(e:whoami:)"
 				// Even though 'ls' might be allowed, the dangerous pattern prevents auto-approval
 				expect(getCommandDecision(globExploit, ["ls", "echo"], [])).toBe("ask_user")
+				// Plus-shorthand form should also prevent auto-approval
+				expect(getCommandDecision("ls *(+whoami)", ["ls", "echo"], [])).toBe("ask_user")
 				// Zsh extended glob with qualifier list and brace-arg form
 				expect(getCommandDecision("ls *(.e{'whoami'})", ["ls", "echo"], [])).toBe("ask_user")
 
diff --git a/webview-ui/src/utils/command-validation.ts b/webview-ui/src/utils/command-validation.ts
index b92aba0d36..9b4f93dad9 100644
--- a/webview-ui/src/utils/command-validation.ts
+++ b/webview-ui/src/utils/command-validation.ts
@@ -115,6 +115,12 @@ export function containsDangerousSubstitution(source: string): boolean {
 	// Any appearance of an "e" qualifier with an argument inside a glob qualifier list is dangerous.
 	const zshGlobQualifier = /\([^)]*e\s*(?::[^:]*:|\{[^}]*\}|'[^']*'|"[^"]*")[^)]*\)/.test(source)
 
+	// Check for zsh glob qualifier shorthand that executes code using +command during glob expansion
+	// Examples: *(+whoami), *(.+{'whoami'}), *(+"whoami")
+	// Treat + followed by a non-digit token inside a qualifier list as executable (exclude numeric-only like (+1))
+	const zshGlobQualifierPlusShorthand =
+		/[?*@+!]\([^)]*\+\s*(?:\{[^}]*\}|'[^']*'|"[^"]*"|[a-zA-Z_][^)\s]*)[^)]*\)/.test(source)
+
 	// Check for $"..." string interpolation with command substitution
 	// $"..." is a bash feature for translated strings that allows command substitution inside
 	// e.g., echo $"test$(whoami)" or echo $"test`pwd`"
@@ -128,6 +134,7 @@ export function containsDangerousSubstitution(source: string): boolean {
 		hereStringWithSubstitution ||
 		zshProcessSubstitution ||
 		zshGlobQualifier ||
+		zshGlobQualifierPlusShorthand ||
 		bashTranslatedStringWithSubstitution
 	)
 }

From 04e16f3f1e340793fcdd4da1b8d345379a4b865d Mon Sep 17 00:00:00 2001
From: John Richmond <5629+jr@users.noreply.github.com>
Date: Mon, 29 Sep 2025 16:04:04 -0700
Subject: [PATCH 5/9] Even more (fish shell this time)

---
 .../utils/__tests__/command-validation.spec.ts    | 11 +++++++++++
 webview-ui/src/utils/command-validation.ts        | 15 +++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/webview-ui/src/utils/__tests__/command-validation.spec.ts b/webview-ui/src/utils/__tests__/command-validation.spec.ts
index acea548e14..2f7b3ba4f7 100644
--- a/webview-ui/src/utils/__tests__/command-validation.spec.ts
+++ b/webview-ui/src/utils/__tests__/command-validation.spec.ts
@@ -41,6 +41,9 @@ describe("Command Validation", () => {
 			expect(parseCommand("npm test $(echo test)")).toEqual(["npm test", "echo test"])
 			expect(parseCommand("npm test `echo test`")).toEqual(["npm test", "echo test"])
 			expect(parseCommand("diff <(sort f1) <(sort f2)")).toEqual(["diff", "sort f1", "sort f2"])
+			// fish-style command substitution using parentheses
+			expect(parseCommand("echo (whoami)")).toEqual(["echo", "whoami"])
+			expect(parseCommand("echo (echo test)")).toEqual(["echo", "echo test"])
 		})
 
 		it("handles nested backticks with escaped inner backticks", () => {
@@ -1097,6 +1100,14 @@ describe("Unified Command Decision Functions", () => {
 			expect(getCommandDecision("echo `echo \\`whoami\\``", ["echo"], [])).toBe("ask_user")
 			// And should be auto-denied when inner command is on the denylist
 			expect(getCommandDecision("echo `echo \\`whoami\\``", ["echo"], ["whoami"])).toBe("auto_deny")
+
+			// Fish-style substitutions behave like subshells
+			expect(getCommandDecision("npm install (echo test)", allowedCommands, deniedCommands)).toBe("auto_approve")
+			expect(getCommandDecision("npm install (npm test)", allowedCommands, deniedCommands)).toBe("auto_deny")
+
+			// Ensure hidden subshell commands are validated even if outer command is allowed
+			expect(getCommandDecision("echo (whoami)", ["echo", "ls"], [])).toBe("ask_user")
+			expect(getCommandDecision("echo (whoami)", ["echo", "ls"], ["whoami"])).toBe("auto_deny")
 		})
 
 		it("properly validates subshell commands when no denylist is present", () => {
diff --git a/webview-ui/src/utils/command-validation.ts b/webview-ui/src/utils/command-validation.ts
index 9b4f93dad9..f309722991 100644
--- a/webview-ui/src/utils/command-validation.ts
+++ b/webview-ui/src/utils/command-validation.ts
@@ -273,6 +273,21 @@ function parseCommandLine(command: string): string[] {
 			return `__SUBSH_${subshells.length - 1}__`
 		})
 
+	// Handle fish-style command substitutions and POSIX subshell grouping: ( ... )
+	// At this point we've already replaced $(), <() and >() earlier, so any remaining (...) are either
+	// fish command substitutions or subshell groupings. We treat them as subshells to validate inner commands.
+	processedCommand = processedCommand.replace(/\(([^()]*)\)/g, (full, inner: string, offset: number, str: string) => {
+		// If this was actually a pattern preceded by $, < or > it would have been handled earlier.
+		// Guard anyway: if the preceding character indicates a different construct, keep original.
+		const prevChar = offset > 0 ? str[offset - 1] : ""
+		if (prevChar === "$" || prevChar === "<" || prevChar === ">") {
+			return full
+		}
+		const content = (inner || "").trim()
+		if (!content) return full
+		subshells.push(content)
+		return `__SUBSH_${subshells.length - 1}__`
+	})
 	// Then handle quoted strings
 	processedCommand = processedCommand.replace(/"[^"]*"/g, (match) => {
 		quotes.push(match)

From 5152e12a16bf57c1858e63d5b6a5f6d63dcb958b Mon Sep 17 00:00:00 2001
From: John Richmond <5629+jr@users.noreply.github.com>
Date: Mon, 29 Sep 2025 16:23:07 -0700
Subject: [PATCH 6/9] more esoteric still

---
 .../__tests__/command-validation.spec.ts      |  14 +++
 webview-ui/src/utils/command-validation.ts    | 108 +++++++++++++++++-
 2 files changed, 116 insertions(+), 6 deletions(-)

diff --git a/webview-ui/src/utils/__tests__/command-validation.spec.ts b/webview-ui/src/utils/__tests__/command-validation.spec.ts
index 2f7b3ba4f7..d432c143fc 100644
--- a/webview-ui/src/utils/__tests__/command-validation.spec.ts
+++ b/webview-ui/src/utils/__tests__/command-validation.spec.ts
@@ -578,6 +578,11 @@ echo "Successfully converted $count .jsx files to .tsx"`
 			expect(result).toEqual(["total=$((price * quantity + tax))"])
 		})
 
+		it("extracts subshells inside arithmetic expressions", () => {
+			const cmd = "arr=(); echo $((arr[$(whoami)]))"
+			expect(parseCommand(cmd)).toEqual(["arr=()", "echo $((arr[$(whoami)]))", "whoami"])
+		})
+
 		it("should handle complex parameter expansions without errors", () => {
 			const commands = [
 				"echo ${var:-default}",
@@ -1110,6 +1115,15 @@ describe("Unified Command Decision Functions", () => {
 			expect(getCommandDecision("echo (whoami)", ["echo", "ls"], ["whoami"])).toBe("auto_deny")
 		})
 
+		it("flags subshell commands inside arithmetic expressions", () => {
+			// When whoami appears inside $(( ... )) via $(whoami), it must be validated
+			expect(getCommandDecision("arr=(); echo $((arr[$(whoami)]))", ["echo", "arr="], [])).toBe("ask_user")
+			// If whoami is explicitly denied, the whole chain must be auto-denied
+			expect(getCommandDecision("arr=(); echo $((arr[$(whoami)]))", ["echo", "arr="], ["whoami"])).toBe(
+				"auto_deny",
+			)
+		})
+
 		it("properly validates subshell commands when no denylist is present", () => {
 			expect(getCommandDecision("npm install $(echo test)", allowedCommands)).toBe("auto_approve")
 			expect(getCommandDecision("npm install `echo test`", allowedCommands)).toBe("auto_approve")
diff --git a/webview-ui/src/utils/command-validation.ts b/webview-ui/src/utils/command-validation.ts
index f309722991..6f9aa2e79c 100644
--- a/webview-ui/src/utils/command-validation.ts
+++ b/webview-ui/src/utils/command-validation.ts
@@ -214,6 +214,8 @@ function parseCommandLine(command: string): string[] {
 	const arithmeticExpressions: string[] = []
 	const variables: string[] = []
 	const parameterExpansions: string[] = []
+	// Commands extracted from within arithmetic expressions (e.g., $(whoami) inside $((...)))
+	const embeddedSubshellCommands: string[] = []
 
 	// First handle PowerShell redirections by temporarily replacing them
 	let processedCommand = command.replace(/\d*>&\d*/g, (match) => {
@@ -221,15 +223,104 @@ function parseCommandLine(command: string): string[] {
 		return `__REDIR_${redirections.length - 1}__`
 	})
 
-	// Handle arithmetic expressions: $((...)) pattern
-	// Match the entire arithmetic expression including nested parentheses
-	processedCommand = processedCommand.replace(/\$\(\([^)]*(?:\)[^)]*)*\)\)/g, (match) => {
-		arithmeticExpressions.push(match)
-		return `__ARITH_${arithmeticExpressions.length - 1}__`
+	// Protect bash array empty initializer in assignments: name=()
+	// Without this, shell-quote may split it into "name=", "(" and ")"
+	processedCommand = processedCommand.replace(/=\s*\(\s*\)/g, (_match) => {
+		arrayIndexing.push("()")
+		return `=__ARRAY_${arrayIndexing.length - 1}__`
 	})
 
+	// Handle arithmetic expressions: $((...)) pattern with balanced parsing.
+	// We must protect the whole arithmetic region from shell-quote tokenization
+	// while still discovering any $(...) or backticks inside it.
+	{
+		let out = ""
+		for (let i = 0; i < processedCommand.length; i++) {
+			// Detect start of $(( ... ))
+			if (processedCommand[i] === "$" && processedCommand[i + 1] === "(" && processedCommand[i + 2] === "(") {
+				const start = i
+				// Track balanced parentheses depth. We saw "(("
+				let depth = 2
+				i += 3
+				while (i < processedCommand.length && depth > 0) {
+					const ch = processedCommand[i]
+					if (ch === "(") depth++
+					else if (ch === ")") depth--
+					i++
+				}
+				// i currently points to the char AFTER the one that closed depth to 0
+				const match = processedCommand.slice(start, i)
+				// Extract subshells $(...) inside arithmetic, but skip arithmetic "$((" by requiring next char != "("
+				match.replace(/\$\((?!\()(.*?)\)/g, (_m, inner) => {
+					const trimmed = String(inner).trim()
+					if (trimmed) {
+						subshells.push(trimmed)
+						const expanded = parseCommand(trimmed)
+						if (expanded.length > 0) {
+							embeddedSubshellCommands.push(...expanded)
+						} else {
+							embeddedSubshellCommands.push(trimmed)
+						}
+					}
+					return _m
+				})
+				// Extract backtick subshells inside arithmetic
+				match.replace(/`((?:\\`|[^`])*)`/g, (_m, inner) => {
+					const unescaped = String(inner).replace(/\\`/g, "`").trim()
+					if (unescaped) {
+						subshells.push(unescaped)
+						const expanded = parseCommand(unescaped)
+						if (expanded.length > 0) {
+							embeddedSubshellCommands.push(...expanded)
+						} else {
+							embeddedSubshellCommands.push(unescaped)
+						}
+					}
+					return _m
+				})
+
+				arithmeticExpressions.push(match)
+				out += `__ARITH_${arithmeticExpressions.length - 1}__`
+				// Compensate for loop's i++ after slice end
+				i -= 1
+			} else {
+				out += processedCommand[i]
+			}
+		}
+		processedCommand = out
+	}
+
 	// Handle $[...] arithmetic expressions (alternative syntax)
 	processedCommand = processedCommand.replace(/\$\[[^\]]*\]/g, (match) => {
+		// Extract subshells inside $[ ... ] arithmetic expressions as well
+		// Skip arithmetic "$((" by ensuring char after "$(" is not "("
+		match.replace(/\$\((?!\()(.*?)\)/g, (_m, inner) => {
+			const trimmed = String(inner).trim()
+			if (trimmed) {
+				subshells.push(trimmed)
+				const expanded = parseCommand(trimmed)
+				if (expanded.length > 0) {
+					embeddedSubshellCommands.push(...expanded)
+				} else {
+					embeddedSubshellCommands.push(trimmed)
+				}
+			}
+			return _m
+		})
+		match.replace(/`((?:\\`|[^`])*)`/g, (_m, inner) => {
+			const unescaped = String(inner).replace(/\\`/g, "`").trim()
+			if (unescaped) {
+				subshells.push(unescaped)
+				const expanded = parseCommand(unescaped)
+				if (expanded.length > 0) {
+					embeddedSubshellCommands.push(...expanded)
+				} else {
+					embeddedSubshellCommands.push(unescaped)
+				}
+			}
+			return _m
+		})
+
 		arithmeticExpressions.push(match)
 		return `__ARITH_${arithmeticExpressions.length - 1}__`
 	})
@@ -262,7 +353,8 @@ function parseCommandLine(command: string): string[] {
 
 	// Then handle subshell commands $() and back-ticks
 	processedCommand = processedCommand
-		.replace(/\$\((.*?)\)/g, (_, inner) => {
+		// Handle command substitution, but avoid arithmetic "$((" by requiring next char != "("
+		.replace(/\$\((?!\()(.*?)\)/g, (_, inner) => {
 			subshells.push(inner.trim())
 			return `__SUBSH_${subshells.length - 1}__`
 		})
@@ -364,6 +456,10 @@ function parseCommandLine(command: string): string[] {
 		commands.push(currentCommand.join(" "))
 	}
 
+	// Include any subshell commands discovered inside arithmetic expressions
+	if (embeddedSubshellCommands.length > 0) {
+		commands.push(...embeddedSubshellCommands)
+	}
 	// Restore quotes and redirections
 	return commands.map((cmd) =>
 		restorePlaceholders(

From 80a24ddacf52660d8a92783d2395d40af968ac5b Mon Sep 17 00:00:00 2001
From: John Richmond <5629+jr@users.noreply.github.com>
Date: Mon, 29 Sep 2025 16:43:10 -0700
Subject: [PATCH 7/9] fix null exception

---
 webview-ui/src/utils/command-validation.ts | 30 +++++++++++++++++-----
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/webview-ui/src/utils/command-validation.ts b/webview-ui/src/utils/command-validation.ts
index 6f9aa2e79c..866549820e 100644
--- a/webview-ui/src/utils/command-validation.ts
+++ b/webview-ui/src/utils/command-validation.ts
@@ -372,11 +372,17 @@ function parseCommandLine(command: string): string[] {
 		// If this was actually a pattern preceded by $, < or > it would have been handled earlier.
 		// Guard anyway: if the preceding character indicates a different construct, keep original.
 		const prevChar = offset > 0 ? str[offset - 1] : ""
-		if (prevChar === "$" || prevChar === "<" || prevChar === ">") {
+		// Also skip array initializers like name=(...) which follow '='
+		if (prevChar === "$" || prevChar === "<" || prevChar === ">" || prevChar === "=") {
 			return full
 		}
 		const content = (inner || "").trim()
 		if (!content) return full
+		// Avoid creating nested placeholders like (__SUBSH_0__) -> __SUBSH_1__
+		// Keep original when content is already a subshell placeholder
+		if (/^__SUBSH_\d+__$/.test(content)) {
+			return full
+		}
 		subshells.push(content)
 		return `__SUBSH_${subshells.length - 1}__`
 	})
@@ -433,17 +439,27 @@ function parseCommandLine(command: string): string[] {
 			// Check if it's a subshell placeholder
 			const subshellMatch = token.match(/__SUBSH_(\d+)__/)
 			if (subshellMatch) {
+				// Split current accumulated command before expanding subshell content
 				if (currentCommand.length > 0) {
 					commands.push(currentCommand.join(" "))
 					currentCommand = []
 				}
 				// Expand subshell into its constituent commands to catch nested substitutions
-				const subshellContent = subshells[parseInt(subshellMatch[1])]
-				const expanded = parseCommand(subshellContent)
-				if (expanded.length > 0) {
-					commands.push(...expanded)
-				} else if (subshellContent.trim()) {
-					commands.push(subshellContent.trim())
+				const idx = parseInt(subshellMatch[1], 10)
+				const subshellContent = subshells[idx]
+				if (typeof subshellContent === "string") {
+					const expanded = parseCommand(subshellContent)
+					if (expanded.length > 0) {
+						commands.push(...expanded)
+					} else {
+						const trimmed = subshellContent.trim()
+						if (trimmed) {
+							commands.push(trimmed)
+						}
+					}
+				} else {
+					// No mapping found for this placeholder in current context; keep token as part of command
+					currentCommand.push(token)
 				}
 			} else {
 				currentCommand.push(token)

From 37faf01202770803537d52d430792828eccfce85 Mon Sep 17 00:00:00 2001
From: John Richmond <5629+jr@users.noreply.github.com>
Date: Mon, 29 Sep 2025 19:16:00 -0700
Subject: [PATCH 8/9] gpt5 fixes from review

---
 .../__tests__/command-validation.spec.ts      |  44 +++
 webview-ui/src/utils/command-validation.ts    | 255 +++++++++++++-----
 2 files changed, 226 insertions(+), 73 deletions(-)

diff --git a/webview-ui/src/utils/__tests__/command-validation.spec.ts b/webview-ui/src/utils/__tests__/command-validation.spec.ts
index d432c143fc..3471ee2150 100644
--- a/webview-ui/src/utils/__tests__/command-validation.spec.ts
+++ b/webview-ui/src/utils/__tests__/command-validation.spec.ts
@@ -52,6 +52,19 @@ describe("Command Validation", () => {
 			expect(parseCommand(cmd)).toEqual(["echo", "echo", "whoami"])
 		})
 
+		it("does not treat parentheses inside quotes as subshells", () => {
+			expect(parseCommand('echo "(whoami)"')).toEqual(['echo "(whoami)"'])
+			expect(parseCommand("echo '(date)'")).toEqual(["echo '(date)'"])
+			expect(parseCommand('printf "(x)"')).toEqual(['printf "(x)"'])
+		})
+
+		it("parses POSIX grouping subshell: (cd dir && ls)", () => {
+			expect(parseCommand("(cd dir && ls)")).toEqual(["cd dir", "ls"])
+		})
+
+		it("parses multiple groupings separated by a pipe: (echo a) | (echo b)", () => {
+			expect(parseCommand("(echo a) | (echo b)")).toEqual(["echo a", "echo b"])
+		})
 		it("handles empty and whitespace input", () => {
 			expect(parseCommand("")).toEqual([])
 			expect(parseCommand("	")).toEqual([])
@@ -329,6 +342,11 @@ ls -la || echo "Failed"`
 			expect(containsDangerousSubstitution('ls *(+"whoami")')).toBe(true)
 		})
 
+		it("does not flag non-glob e:...: parenthetical as dangerous", () => {
+			expect(containsDangerousSubstitution("(e:whoami:)")).toBe(false)
+			expect(containsDangerousSubstitution('echo "(e:whoami:)"')).toBe(false)
+		})
+
 		it('detects bash $"..." string interpolation with command substitution', () => {
 			// The exact example from the issue
 			expect(containsDangerousSubstitution('echo $"test$(whoami)"')).toBe(true)
@@ -353,6 +371,10 @@ ls -la || echo "Failed"`
 			expect(containsDangerousSubstitution('echo $"Result: `rm -rf /`"')).toBe(true)
 		})
 
+		it('detects $"..." with escaped quotes and command substitution', () => {
+			expect(containsDangerousSubstitution('echo $"val=\\"$(whoami)\\""')).toBe(true)
+		})
+
 		it("does NOT flag safe parameter expansions", () => {
 			// Regular parameter expansions without dangerous operators
 			expect(containsDangerousSubstitution("echo ${var}")).toBe(false)
@@ -617,6 +639,11 @@ echo "Successfully converted $count .jsx files to .tsx"`
 			})
 		})
 
+		it("should handle process substitutions with nested/quoted parentheses", () => {
+			expect(() => parseCommand('cmd >(grep "(")')).not.toThrow()
+			expect(() => parseCommand('cmd >(grep "\\(foo\\)")')).not.toThrow()
+		})
+
 		it("should handle special bash variables without errors", () => {
 			const commands = [
 				"echo $?",
@@ -1514,3 +1541,20 @@ describe("Unified Command Decision Functions", () => {
 		})
 	})
 })
+
+// Additional regression tests from jr/more-subshells review
+describe("Regression: escaped quotes and process substitution", () => {
+	it("parses double-quoted strings with escaped quotes without splitting", () => {
+		expect(parseCommand('echo "val=\\"x\\""')).toEqual(['echo "val=\\"x\\""'])
+	})
+
+	it("does not flag bash array assignments as zsh process substitution", () => {
+		expect(containsDangerousSubstitution("arr=(a b)")).toBe(false)
+		expect(containsDangerousSubstitution("arr=()")).toBe(false)
+	})
+
+	it("handles escaped quotes inside backticks", () => {
+		const cmd = 'echo `printf \\"%s\\"`'
+		expect(parseCommand(cmd)).toEqual(["echo", 'printf "%s"'])
+	})
+})
diff --git a/webview-ui/src/utils/command-validation.ts b/webview-ui/src/utils/command-validation.ts
index 866549820e..244c85c7cd 100644
--- a/webview-ui/src/utils/command-validation.ts
+++ b/webview-ui/src/utils/command-validation.ts
@@ -105,26 +105,29 @@ export function containsDangerousSubstitution(source: string): boolean {
 
 	// Check for zsh process substitution =(...) which executes commands
 	// =(...) creates a temporary file containing the output of the command, but executes it
-	const zshProcessSubstitution = /=\([^)]+\)/.test(source)
+	// Tightened regex avoids matching bash array assignments like arr=(a b) or arr=() by ensuring
+	// '=' is not immediately preceded by an identifier, ']' or '}'.
+	const zshProcessSubstitution = /(?<![A-Za-z0-9_\]}])=\([^)]+\)/.test(source)
 
 	// Check for zsh glob qualifiers with code execution via the "e" qualifier
-	// This must detect multiple zsh forms that execute code during glob expansion:
+	// This detects multiple zsh forms that execute code during glob expansion:
 	// - Classic: *(e:whoami:) or ?(e:rm -rf /:) etc.
 	// - With other qualifiers: *(.e:whoami:) (dot means "plain files" plus e:...)
 	// - Brace/quoted argument forms: *(e{'whoami'}), *(.e{'whoami'}), *(e{"whoami"}), *(.e{"whoami"})
-	// Any appearance of an "e" qualifier with an argument inside a glob qualifier list is dangerous.
-	const zshGlobQualifier = /\([^)]*e\s*(?::[^:]*:|\{[^}]*\}|'[^']*'|"[^"]*")[^)]*\)/.test(source)
+	// To reduce false positives, require a glob meta right before the qualifier list and ensure it's not escaped.
+	const zshGlobQualifier = /(?<!\\)[*?+@!]\([^)]*\be\s*(?::[^:]*:|\{[^}]*\}|'[^']*'|"[^"]*")[^)]*\)/.test(source)
 
 	// Check for zsh glob qualifier shorthand that executes code using +command during glob expansion
 	// Examples: *(+whoami), *(.+{'whoami'}), *(+"whoami")
 	// Treat + followed by a non-digit token inside a qualifier list as executable (exclude numeric-only like (+1))
+	// Anchor to a preceding glob meta to reduce false positives.
 	const zshGlobQualifierPlusShorthand =
-		/[?*@+!]\([^)]*\+\s*(?:\{[^}]*\}|'[^']*'|"[^"]*"|[a-zA-Z_][^)\s]*)[^)]*\)/.test(source)
+		/(?<!\\)[*?+@!]\([^)]*\+\s*(?:\{[^}]*\}|'[^']*'|"[^"]*"|[a-zA-Z_][^)\s]*)[^)]*\)/.test(source)
 
 	// Check for $"..." string interpolation with command substitution
 	// $"..." is a bash feature for translated strings that allows command substitution inside
-	// e.g., echo $"test$(whoami)" or echo $"test`pwd`"
-	const bashTranslatedStringWithSubstitution = /\$"[^"]*(\$\(|`)[^"]*"/.test(source)
+	// Handle escaped quotes within $"...": use (?:\\.|[^"])* to avoid premature termination on \"
+	const bashTranslatedStringWithSubstitution = /\$"(?:\\.|[^"])*(?:\$\(|`)(?:\\.|[^"])*"/.test(source)
 
 	// Return true if any dangerous pattern is detected
 	return (
@@ -146,6 +149,7 @@ export function containsDangerousSubstitution(source: string): boolean {
  * Uses shell-quote to properly handle:
  * - Quoted strings (preserves quotes)
  * - Subshell commands ($(cmd), `cmd`, <(cmd), >(cmd))
+ * - POSIX grouping subshells ((...)) and fish-style (cmd) substitutions as separate sub-commands
  * - PowerShell redirections (2>&1)
  * - Chain operators (&&, ||, ;, |, &)
  * - Newlines as command separators
@@ -224,10 +228,10 @@ function parseCommandLine(command: string): string[] {
 	})
 
 	// Protect bash array empty initializer in assignments: name=()
-	// Without this, shell-quote may split it into "name=", "(" and ")"
-	processedCommand = processedCommand.replace(/=\s*\(\s*\)/g, (_match) => {
+	// Require an identifier immediately before '=' to avoid matching unrelated patterns like "x = ()"
+	processedCommand = processedCommand.replace(/([A-Za-z_][A-Za-z0-9_]*)\s*=\s*\(\s*\)/g, (_match, name: string) => {
 		arrayIndexing.push("()")
-		return `=__ARRAY_${arrayIndexing.length - 1}__`
+		return `${name}=__ARRAY_${arrayIndexing.length - 1}__`
 	})
 
 	// Handle arithmetic expressions: $((...)) pattern with balanced parsing.
@@ -239,13 +243,21 @@ function parseCommandLine(command: string): string[] {
 			// Detect start of $(( ... ))
 			if (processedCommand[i] === "$" && processedCommand[i + 1] === "(" && processedCommand[i + 2] === "(") {
 				const start = i
-				// Track balanced parentheses depth. We saw "(("
+				// Track balanced parentheses depth with basic quote awareness. We saw "(("
 				let depth = 2
+				let inSingle = false
+				let inDouble = false
 				i += 3
 				while (i < processedCommand.length && depth > 0) {
 					const ch = processedCommand[i]
-					if (ch === "(") depth++
-					else if (ch === ")") depth--
+					if (ch === "'" && !inDouble) {
+						inSingle = !inSingle
+					} else if (ch === '"' && !inSingle) {
+						inDouble = !inDouble
+					} else if (!inSingle && !inDouble) {
+						if (ch === "(") depth++
+						else if (ch === ")") depth--
+					}
 					i++
 				}
 				// i currently points to the char AFTER the one that closed depth to 0
@@ -290,40 +302,64 @@ function parseCommandLine(command: string): string[] {
 		processedCommand = out
 	}
 
-	// Handle $[...] arithmetic expressions (alternative syntax)
-	processedCommand = processedCommand.replace(/\$\[[^\]]*\]/g, (match) => {
-		// Extract subshells inside $[ ... ] arithmetic expressions as well
-		// Skip arithmetic "$((" by ensuring char after "$(" is not "("
-		match.replace(/\$\((?!\()(.*?)\)/g, (_m, inner) => {
-			const trimmed = String(inner).trim()
-			if (trimmed) {
-				subshells.push(trimmed)
-				const expanded = parseCommand(trimmed)
-				if (expanded.length > 0) {
-					embeddedSubshellCommands.push(...expanded)
-				} else {
-					embeddedSubshellCommands.push(trimmed)
-				}
-			}
-			return _m
-		})
-		match.replace(/`((?:\\`|[^`])*)`/g, (_m, inner) => {
-			const unescaped = String(inner).replace(/\\`/g, "`").trim()
-			if (unescaped) {
-				subshells.push(unescaped)
-				const expanded = parseCommand(unescaped)
-				if (expanded.length > 0) {
-					embeddedSubshellCommands.push(...expanded)
-				} else {
-					embeddedSubshellCommands.push(unescaped)
+	// Handle $[...] arithmetic expressions (alternative syntax) with balanced scanning
+	{
+		let out = ""
+		for (let i = 0; i < processedCommand.length; i++) {
+			if (processedCommand[i] === "$" && processedCommand[i + 1] === "[") {
+				const start = i
+				i += 2
+				let depth = 1
+				let inSingle = false
+				let inDouble = false
+				while (i < processedCommand.length && depth > 0) {
+					const ch = processedCommand[i]
+					if (ch === "'" && !inDouble) inSingle = !inSingle
+					else if (ch === '"' && !inSingle) inDouble = !inDouble
+					else if (!inSingle && !inDouble) {
+						if (ch === "[") depth++
+						else if (ch === "]") depth--
+					}
+					i++
 				}
-			}
-			return _m
-		})
+				const match = processedCommand.slice(start, i)
+				// Extract subshells inside $[ ... ] arithmetic expressions as well
+				match.replace(/\$\((?!\()(.*?)\)/g, (_m, inner) => {
+					const trimmed = String(inner).trim()
+					if (trimmed) {
+						subshells.push(trimmed)
+						const expanded = parseCommand(trimmed)
+						if (expanded.length > 0) {
+							embeddedSubshellCommands.push(...expanded)
+						} else {
+							embeddedSubshellCommands.push(trimmed)
+						}
+					}
+					return _m
+				})
+				match.replace(/`((?:\\`|[^`])*)`/g, (_m, inner) => {
+					const unescaped = String(inner).replace(/\\`/g, "`").trim()
+					if (unescaped) {
+						subshells.push(unescaped)
+						const expanded = parseCommand(unescaped)
+						if (expanded.length > 0) {
+							embeddedSubshellCommands.push(...expanded)
+						} else {
+							embeddedSubshellCommands.push(unescaped)
+						}
+					}
+					return _m
+				})
 
-		arithmeticExpressions.push(match)
-		return `__ARITH_${arithmeticExpressions.length - 1}__`
-	})
+				arithmeticExpressions.push(match)
+				out += `__ARITH_${arithmeticExpressions.length - 1}__`
+				i -= 1
+			} else {
+				out += processedCommand[i]
+			}
+		}
+		processedCommand = out
+	}
 
 	// Handle parameter expansions: ${...} patterns (including array indexing)
 	// This covers ${var}, ${var:-default}, ${var:+alt}, ${#var}, ${var%pattern}, etc.
@@ -332,11 +368,40 @@ function parseCommandLine(command: string): string[] {
 		return `__PARAM_${parameterExpansions.length - 1}__`
 	})
 
-	// Handle process substitutions: <(...) and >(...)
-	processedCommand = processedCommand.replace(/[<>]\(([^)]+)\)/g, (_, inner) => {
-		subshells.push(inner.trim())
-		return `__SUBSH_${subshells.length - 1}__`
-	})
+	// Handle process substitutions: <(...) and >(...) with balanced scanning
+	{
+		let out = ""
+		for (let i = 0; i < processedCommand.length; i++) {
+			if ((processedCommand[i] === "<" || processedCommand[i] === ">") && processedCommand[i + 1] === "(") {
+				const start = i
+				i += 2
+				let depth = 1
+				let inSingle = false
+				let inDouble = false
+				while (i < processedCommand.length && depth > 0) {
+					const ch = processedCommand[i]
+					if (ch === "'" && !inDouble) inSingle = !inSingle
+					else if (ch === '"' && !inSingle) inDouble = !inDouble
+					else if (!inSingle && !inDouble) {
+						if (ch === "(") depth++
+						else if (ch === ")") depth--
+					}
+					i++
+				}
+				const inner = processedCommand.slice(start + 2, i - 1).trim()
+				if (inner) {
+					subshells.push(inner)
+					out += `__SUBSH_${subshells.length - 1}__`
+				} else {
+					out += processedCommand.slice(start, i)
+				}
+				i -= 1
+			} else {
+				out += processedCommand[i]
+			}
+		}
+		processedCommand = out
+	}
 
 	// Handle simple variable references: $varname pattern
 	// This prevents shell-quote from splitting $count into separate tokens
@@ -365,39 +430,79 @@ function parseCommandLine(command: string): string[] {
 			return `__SUBSH_${subshells.length - 1}__`
 		})
 
-	// Handle fish-style command substitutions and POSIX subshell grouping: ( ... )
-	// At this point we've already replaced $(), <() and >() earlier, so any remaining (...) are either
-	// fish command substitutions or subshell groupings. We treat them as subshells to validate inner commands.
-	processedCommand = processedCommand.replace(/\(([^()]*)\)/g, (full, inner: string, offset: number, str: string) => {
-		// If this was actually a pattern preceded by $, < or > it would have been handled earlier.
-		// Guard anyway: if the preceding character indicates a different construct, keep original.
-		const prevChar = offset > 0 ? str[offset - 1] : ""
-		// Also skip array initializers like name=(...) which follow '='
-		if (prevChar === "$" || prevChar === "<" || prevChar === ">" || prevChar === "=") {
-			return full
-		}
-		const content = (inner || "").trim()
-		if (!content) return full
-		// Avoid creating nested placeholders like (__SUBSH_0__) -> __SUBSH_1__
-		// Keep original when content is already a subshell placeholder
-		if (/^__SUBSH_\d+__$/.test(content)) {
-			return full
-		}
-		subshells.push(content)
-		return `__SUBSH_${subshells.length - 1}__`
+	// Mask quoted strings BEFORE handling fish-style parentheses to avoid false subshells inside quotes
+	processedCommand = processedCommand.replace(/"((?:\\.|[^"\\])*)"/g, (match) => {
+		quotes.push(match)
+		return `__QUOTE_${quotes.length - 1}__`
 	})
-	// Then handle quoted strings
-	processedCommand = processedCommand.replace(/"[^"]*"/g, (match) => {
+	// Also mask single-quoted strings before handling parentheses
+	processedCommand = processedCommand.replace(/'[^']*'/g, (match) => {
 		quotes.push(match)
 		return `__QUOTE_${quotes.length - 1}__`
 	})
 
+	// Handle fish-style command substitutions and POSIX subshell grouping: ( ... )
+	// Use balanced scanning to support nested parentheses while respecting quotes.
+	// We already handled $(), <() and >() earlier, so remaining (...) are either fish substitutions or groupings.
+	{
+		let out = ""
+		for (let i = 0; i < processedCommand.length; i++) {
+			const ch = processedCommand[i]
+			if (ch === "(") {
+				const prevChar = i > 0 ? processedCommand[i - 1] : ""
+				// Skip constructs that were or will be handled elsewhere
+				if (prevChar === "$" || prevChar === "<" || prevChar === ">" || prevChar === "=") {
+					out += ch
+					continue
+				}
+				let j = i + 1
+				let depth = 1
+				let inSingle = false
+				let inDouble = false
+				while (j < processedCommand.length && depth > 0) {
+					const cj = processedCommand[j]
+					if (cj === "'" && !inDouble) inSingle = !inSingle
+					else if (cj === '"' && !inSingle) inDouble = !inDouble
+					else if (!inSingle && !inDouble) {
+						if (cj === "(") depth++
+						else if (cj === ")") depth--
+					}
+					j++
+				}
+				if (depth === 0) {
+					const inner = processedCommand.slice(i + 1, j - 1).trim()
+					if (inner) {
+						// Avoid generating placeholder around an existing subshell placeholder
+						if (/^__SUBSH_\d+__$/.test(inner)) {
+							out += processedCommand.slice(i, j)
+						} else {
+							subshells.push(inner)
+							out += `__SUBSH_${subshells.length - 1}__`
+						}
+					} else {
+						// Empty grouping, keep as-is
+						out += processedCommand.slice(i, j)
+					}
+					i = j - 1
+				} else {
+					// Unbalanced; keep the '(' and continue
+					out += ch
+				}
+			} else {
+				out += ch
+			}
+		}
+		processedCommand = out
+	}
+
 	let tokens: ShellToken[]
 	try {
 		tokens = parse(processedCommand) as ShellToken[]
 	} catch (error: any) {
 		// If shell-quote fails to parse, fall back to simple splitting
-		console.warn("shell-quote parse error:", error.message, "for command:", processedCommand)
+		if (typeof process !== "undefined" && process.env?.NODE_ENV !== "production") {
+			console.warn("shell-quote parse error:", error.message, "for command:", processedCommand)
+		}
 
 		// Simple fallback: split by common operators
 		const fallbackCommands = processedCommand
@@ -662,6 +767,10 @@ export type CommandDecision = "auto_approve" | "auto_deny" | "ask_user"
  * // Returns "ask_user"
  * ```
  *
+ * Ordering note: parseCommand appends subshell commands discovered inside arithmetic expressions
+ * to the end of the subCommands list. Since any denial results in an auto_deny decision, this
+ * ordering does not affect outcomes, but is documented here for clarity.
+ *
  * @param command - The full command string to validate
  * @param allowedCommands - List of allowed command prefixes
  * @param deniedCommands - Optional list of denied command prefixes

From c9c43335895fd02da7e003fc23aa2240b3eb0606 Mon Sep 17 00:00:00 2001
From: John Richmond <5629+jr@users.noreply.github.com>
Date: Mon, 29 Sep 2025 20:55:49 -0700
Subject: [PATCH 9/9] Potential fix for code scanning alert no. 189:
 Inefficient regular expression

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>
---
 webview-ui/src/utils/command-validation.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/webview-ui/src/utils/command-validation.ts b/webview-ui/src/utils/command-validation.ts
index 244c85c7cd..6596e4a853 100644
--- a/webview-ui/src/utils/command-validation.ts
+++ b/webview-ui/src/utils/command-validation.ts
@@ -127,7 +127,7 @@ export function containsDangerousSubstitution(source: string): boolean {
 	// Check for $"..." string interpolation with command substitution
 	// $"..." is a bash feature for translated strings that allows command substitution inside
 	// Handle escaped quotes within $"...": use (?:\\.|[^"])* to avoid premature termination on \"
-	const bashTranslatedStringWithSubstitution = /\$"(?:\\.|[^"])*(?:\$\(|`)(?:\\.|[^"])*"/.test(source)
+	const bashTranslatedStringWithSubstitution = /\$"(?:\\.|[^\\"])*(?:\$\(|`)(?:\\.|[^\\"])*"/.test(source)
 
 	// Return true if any dangerous pattern is detected
 	return (