diff --git a/packages/playground/cli/src/is-valid-wordpress-slug.ts b/packages/playground/cli/src/is-valid-wordpress-slug.ts
index 4fdd957961..0538138982 100644
--- a/packages/playground/cli/src/is-valid-wordpress-slug.ts
+++ b/packages/playground/cli/src/is-valid-wordpress-slug.ts
@@ -4,6 +4,7 @@
  * The Regex is based on the releases on https://wordpress.org/download/releases/#betas
  * The version string can be one of the following formats:
  * - "latest"
+ * - "beta"
  * - "trunk"
  * - "nightly"
  * - "x.y" (x and y are integers) e.g. "6.2"
@@ -16,6 +17,6 @@
  */
 export function isValidWordPressSlug(version: string): boolean {
 	const versionPattern =
-		/^latest$|^trunk$|^nightly$|^(?:(\d+)\.(\d+)(?:\.(\d+))?)((?:-beta(?:\d+)?)|(?:-RC(?:\d+)?))?$/;
+		/^latest$|^beta$|^trunk$|^nightly$|^(?:(\d+)\.(\d+)(?:\.(\d+))?)((?:-beta(?:\d+)?)|(?:-RC(?:\d+)?))?$/;
 	return versionPattern.test(version);
 }
diff --git a/packages/playground/cli/src/run-cli.ts b/packages/playground/cli/src/run-cli.ts
index 93b4f4f35f..f9271b2098 100644
--- a/packages/playground/cli/src/run-cli.ts
+++ b/packages/playground/cli/src/run-cli.ts
@@ -263,7 +263,7 @@ export async function parseOptionsAndRunCLI() {
 						new URL(args.wp);
 					} catch {
 						throw new Error(
-							'Unrecognized WordPress version. Please use "latest", a URL, or a numeric version such as "6.2", "6.0.1", "6.2-beta1", or "6.2-RC1"'
+							'Unrecognized WordPress version. Please use "latest", "beta", "trunk", "nightly", a URL, or a numeric version such as "6.2", "6.0.1", "6.2-beta1", or "6.2-RC1"'
 						);
 					}
 				}
diff --git a/packages/playground/cli/tests/is-valid-wordpress-slug.spec.ts b/packages/playground/cli/tests/is-valid-wordpress-slug.spec.ts
new file mode 100644
index 0000000000..615f5e2873
--- /dev/null
+++ b/packages/playground/cli/tests/is-valid-wordpress-slug.spec.ts
@@ -0,0 +1,60 @@
+import { describe, it, expect } from 'vitest';
+import { isValidWordPressSlug } from '../src/is-valid-wordpress-slug';
+
+describe('isValidWordPressSlug', () => {
+	it('should accept "latest"', () => {
+		expect(isValidWordPressSlug('latest')).toBe(true);
+	});
+
+	it('should accept "beta"', () => {
+		expect(isValidWordPressSlug('beta')).toBe(true);
+	});
+
+	it('should accept "trunk"', () => {
+		expect(isValidWordPressSlug('trunk')).toBe(true);
+	});
+
+	it('should accept "nightly"', () => {
+		expect(isValidWordPressSlug('nightly')).toBe(true);
+	});
+
+	it('should accept version with major and minor (e.g., "6.2")', () => {
+		expect(isValidWordPressSlug('6.2')).toBe(true);
+		expect(isValidWordPressSlug('5.9')).toBe(true);
+	});
+
+	it('should accept version with major, minor, and patch (e.g., "6.2.1")', () => {
+		expect(isValidWordPressSlug('6.2.1')).toBe(true);
+		expect(isValidWordPressSlug('5.9.3')).toBe(true);
+	});
+
+	it('should accept version with beta suffix (e.g., "6.2-beta1")', () => {
+		expect(isValidWordPressSlug('6.2-beta1')).toBe(true);
+		expect(isValidWordPressSlug('6.2.1-beta1')).toBe(true);
+		expect(isValidWordPressSlug('6.2-beta')).toBe(true);
+	});
+
+	it('should accept version with RC suffix (e.g., "6.2-RC1")', () => {
+		expect(isValidWordPressSlug('6.2-RC1')).toBe(true);
+		expect(isValidWordPressSlug('6.2.1-RC1')).toBe(true);
+		expect(isValidWordPressSlug('6.2-RC')).toBe(true);
+	});
+
+	it('should reject invalid version strings', () => {
+		expect(isValidWordPressSlug('brazil')).toBe(false);
+		expect(isValidWordPressSlug('invalid')).toBe(false);
+		expect(isValidWordPressSlug('beta1')).toBe(false);
+		expect(isValidWordPressSlug('RC1')).toBe(false);
+		expect(isValidWordPressSlug('6')).toBe(false);
+		expect(isValidWordPressSlug('6.x')).toBe(false);
+		expect(isValidWordPressSlug('6.2.x')).toBe(false);
+		expect(isValidWordPressSlug('')).toBe(false);
+	});
+
+	it('should reject version with invalid format', () => {
+		expect(isValidWordPressSlug('6.2.1.2')).toBe(false);
+		expect(isValidWordPressSlug('v6.2')).toBe(false);
+		expect(isValidWordPressSlug('6.2-alpha')).toBe(false);
+		expect(isValidWordPressSlug('6.2-beta-1')).toBe(false);
+	});
+});
diff --git a/packages/playground/cli/tests/run-cli-validation.spec.ts b/packages/playground/cli/tests/run-cli-validation.spec.ts
new file mode 100644
index 0000000000..58976f7058
--- /dev/null
+++ b/packages/playground/cli/tests/run-cli-validation.spec.ts
@@ -0,0 +1,76 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { parseOptionsAndRunCLI } from '../src/run-cli';
+
+describe('parseOptionsAndRunCLI WordPress version validation', () => {
+	let originalArgv: string[];
+	let exitSpy: ReturnType<typeof vi.spyOn>;
+	let consoleErrorSpy: ReturnType<typeof vi.spyOn>;
+
+	beforeEach(() => {
+		originalArgv = process.argv;
+		exitSpy = vi.spyOn(process, 'exit').mockImplementation((() => {
+			throw new Error('process.exit called');
+		}) as any);
+		consoleErrorSpy = vi
+			.spyOn(console, 'error')
+			.mockImplementation(() => {});
+	});
+
+	afterEach(() => {
+		process.argv = originalArgv;
+		exitSpy.mockRestore();
+		consoleErrorSpy.mockRestore();
+	});
+
+	it('should reject invalid WordPress version "brazil"', async () => {
+		process.argv = ['node', 'cli.js', 'server', '--wp=brazil'];
+
+		await expect(parseOptionsAndRunCLI()).rejects.toThrow(
+			'process.exit called'
+		);
+
+		expect(consoleErrorSpy).toHaveBeenCalled();
+		const errorMessage = consoleErrorSpy.mock.calls[0][0];
+		expect(errorMessage).toContain('Unrecognized WordPress version');
+	});
+
+	it('should reject invalid WordPress version "invalid-version"', async () => {
+		process.argv = ['node', 'cli.js', 'server', '--wp=invalid-version'];
+
+		await expect(parseOptionsAndRunCLI()).rejects.toThrow(
+			'process.exit called'
+		);
+
+		expect(consoleErrorSpy).toHaveBeenCalled();
+		const errorMessage = consoleErrorSpy.mock.calls[0][0];
+		expect(errorMessage).toContain('Unrecognized WordPress version');
+	});
+
+	it('should accept valid WordPress version "beta"', async () => {
+		process.argv = [
+			'node',
+			'cli.js',
+			'server',
+			'--wp=beta',
+			'--skip-wordpress-setup',
+		];
+
+		// This test would actually start the server, so we skip it in unit tests
+		// The important part is that it doesn't throw a validation error
+		// We'll rely on integration tests to verify the full flow
+	});
+
+	it('should accept valid WordPress version "latest"', async () => {
+		process.argv = [
+			'node',
+			'cli.js',
+			'server',
+			'--wp=latest',
+			'--skip-wordpress-setup',
+		];
+
+		// This test would actually start the server, so we skip it in unit tests
+		// The important part is that it doesn't throw a validation error
+		// We'll rely on integration tests to verify the full flow
+	});
+});
diff --git a/packages/playground/cli/tests/run-cli.spec.ts b/packages/playground/cli/tests/run-cli.spec.ts
index c9dcf13071..01d80a8520 100644
--- a/packages/playground/cli/tests/run-cli.spec.ts
+++ b/packages/playground/cli/tests/run-cli.spec.ts
@@ -690,4 +690,42 @@ describe('other run-cli behaviors', () => {
 			expect(response.status).toBe(500);
 		});
 	});
+
+	describe('WordPress version validation', () => {
+		test('should accept "latest" as a valid WordPress version', async () => {
+			cliServer = await runCLI({
+				...suiteCliArgs,
+				command: 'server',
+				wp: 'latest',
+			});
+			expect(cliServer).toBeDefined();
+		});
+
+		test('should accept "beta" as a valid WordPress version', async () => {
+			cliServer = await runCLI({
+				...suiteCliArgs,
+				command: 'server',
+				wp: 'beta',
+			});
+			expect(cliServer).toBeDefined();
+		});
+
+		test('should accept numeric version as valid WordPress version', async () => {
+			cliServer = await runCLI({
+				...suiteCliArgs,
+				command: 'server',
+				wp: '6.2',
+			});
+			expect(cliServer).toBeDefined();
+		});
+
+		test('should accept valid URL as WordPress version', async () => {
+			cliServer = await runCLI({
+				...suiteCliArgs,
+				command: 'server',
+				wp: 'https://downloads.wordpress.org/release/wordpress-6.2.zip',
+			});
+			expect(cliServer).toBeDefined();
+		});
+	});
 });