diff --git a/FirebaseAuth.podspec b/FirebaseAuth.podspec
index 7c20069bd41..1f16ebcad86 100644
--- a/FirebaseAuth.podspec
+++ b/FirebaseAuth.podspec
@@ -61,7 +61,7 @@ supports email and password accounts, as well as several 3rd party authenticatio
   s.dependency 'FirebaseCoreExtension', '~> 12.0.0'
   s.dependency 'GoogleUtilities/AppDelegateSwizzler', '~> 8.1'
   s.dependency 'GoogleUtilities/Environment', '~> 8.1'
-  s.dependency 'GTMSessionFetcher/Core', '>= 3.4', '< 5.0'
+  s.dependency 'GTMSessionFetcher/Core', '>= 3.4', '< 6.0'
   s.ios.dependency 'RecaptchaInterop', '~> 101.0'
   s.test_spec 'unit' do |unit_tests|
     unit_tests.scheme = { :code_coverage => true }
diff --git a/FirebaseAuth/Tests/SampleSwift/AuthenticationExample.xcodeproj/project.pbxproj b/FirebaseAuth/Tests/SampleSwift/AuthenticationExample.xcodeproj/project.pbxproj
index f6a45f1b931..c34b5cec198 100644
--- a/FirebaseAuth/Tests/SampleSwift/AuthenticationExample.xcodeproj/project.pbxproj
+++ b/FirebaseAuth/Tests/SampleSwift/AuthenticationExample.xcodeproj/project.pbxproj
@@ -998,6 +998,7 @@
 			requirement = {
 				kind = upToNextMajorVersion;
 				minimumVersion = 3.4.1;
+				maximumVersion = "6.0.0";
 			};
 		};
 /* End XCRemoteSwiftPackageReference section */
diff --git a/FirebaseCore/CHANGELOG.md b/FirebaseCore/CHANGELOG.md
index 16c8c30b0ce..a7dbe44f062 100644
--- a/FirebaseCore/CHANGELOG.md
+++ b/FirebaseCore/CHANGELOG.md
@@ -31,6 +31,8 @@
   ](https://firebase.google.com/docs/ai-logic/migrate-to-latest-sdk).
 - [changed] **Breaking change** The Firebase Swift package now requires the
   Swift 6.0 toolchain (Xcode 16.2+).
+- [changed] Update GTMSessionFetcher dependency specifications to enable
+  support for the compatible GTMSessionFetcher 5.x versions.
 
 # Firebase 11.15.0
 - [fixed] Remove c99 as the required C language standard. (#14950)
diff --git a/FirebaseFunctions.podspec b/FirebaseFunctions.podspec
index e5d93cb78c4..f75ae1f809d 100644
--- a/FirebaseFunctions.podspec
+++ b/FirebaseFunctions.podspec
@@ -41,7 +41,7 @@ Cloud Functions for Firebase.
   s.dependency 'FirebaseAuthInterop', '~> 12.0.0'
   s.dependency 'FirebaseMessagingInterop', '~> 12.0.0'
   s.dependency 'FirebaseSharedSwift', '~> 12.0.0'
-  s.dependency 'GTMSessionFetcher/Core', '>= 3.4', '< 5.0'
+  s.dependency 'GTMSessionFetcher/Core', '>= 3.4', '< 6.0'
 
   s.test_spec 'objc' do |objc_tests|
     objc_tests.platforms = {
diff --git a/FirebaseStorage.podspec b/FirebaseStorage.podspec
index 3f787367cad..9c9561b7335 100644
--- a/FirebaseStorage.podspec
+++ b/FirebaseStorage.podspec
@@ -41,7 +41,7 @@ Firebase Storage provides robust, secure file uploads and downloads from Firebas
   s.dependency 'FirebaseAuthInterop', '~> 12.0.0'
   s.dependency 'FirebaseCore', '~> 12.0.0'
   s.dependency 'FirebaseCoreExtension', '~> 12.0.0'
-  s.dependency 'GTMSessionFetcher/Core', '>= 3.4', '< 5.0'
+  s.dependency 'GTMSessionFetcher/Core', '>= 3.4', '< 6.0'
   s.dependency 'GoogleUtilities/Environment', '~> 8.1'
 
   s.test_spec 'ObjCIntegration' do |objc_tests|
diff --git a/Package.swift b/Package.swift
index 9cb624a571a..3638c29b089 100644
--- a/Package.swift
+++ b/Package.swift
@@ -141,7 +141,7 @@ let package = Package(
     ),
     .package(
       url: "https://github.com/google/gtm-session-fetcher.git",
-      "3.4.1" ..< "5.0.0"
+      "3.4.1" ..< "6.0.0"
     ),
     .package(
       url: "https://github.com/firebase/nanopb.git",