diff --git a/packages/cli/src/gemini.test.tsx b/packages/cli/src/gemini.test.tsx
index 69ea6db56e..fd19ffa79c 100644
--- a/packages/cli/src/gemini.test.tsx
+++ b/packages/cli/src/gemini.test.tsx
@@ -528,6 +528,62 @@ describe('gemini.tsx main function kitty protocol', () => {
     );
   });
 
+  it('should call process.stdin.resume when isInteractive is true to protect against implicit Node pause', async () => {
+    const resumeSpy = vi.spyOn(process.stdin, 'resume');
+    vi.mocked(loadCliConfig).mockResolvedValue(
+      createMockConfig({
+        isInteractive: () => true,
+        getQuestion: () => '',
+        getSandbox: () => undefined,
+      }),
+    );
+    vi.mocked(loadSettings).mockReturnValue(
+      createMockSettings({
+        merged: {
+          advanced: {},
+          security: { auth: {} },
+          ui: {},
+        },
+      }),
+    );
+    vi.mocked(parseArguments).mockResolvedValue({
+      model: undefined,
+      sandbox: undefined,
+      debug: undefined,
+      prompt: undefined,
+      promptInteractive: undefined,
+      query: undefined,
+      yolo: undefined,
+      approvalMode: undefined,
+      policy: undefined,
+      adminPolicy: undefined,
+      allowedMcpServerNames: undefined,
+      allowedTools: undefined,
+      experimentalAcp: undefined,
+      extensions: undefined,
+      listExtensions: undefined,
+      includeDirectories: undefined,
+      screenReader: undefined,
+      useWriteTodos: undefined,
+      resume: undefined,
+      listSessions: undefined,
+      deleteSession: undefined,
+      outputFormat: undefined,
+      fakeResponses: undefined,
+      recordResponses: undefined,
+      rawOutput: undefined,
+      acceptRawOutputRisk: undefined,
+      isCommand: undefined,
+    });
+
+    await act(async () => {
+      await main();
+    });
+
+    expect(resumeSpy).toHaveBeenCalledTimes(1);
+    resumeSpy.mockRestore();
+  });
+
   it.each([
     { flag: 'listExtensions' },
     { flag: 'listSessions' },
diff --git a/packages/cli/src/gemini.tsx b/packages/cli/src/gemini.tsx
index 707774df57..4b43d7d81b 100644
--- a/packages/cli/src/gemini.tsx
+++ b/packages/cli/src/gemini.tsx
@@ -613,8 +613,17 @@ export async function main() {
     }
 
     cliStartupHandle?.end();
+
     // Render UI, passing necessary config values. Check that there is no command line question.
     if (config.isInteractive()) {
+      // Earlier initialization phases (like TerminalCapabilityManager resolving
+      // or authWithWeb) may have added and removed 'data' listeners on process.stdin.
+      // When the listener count drops to 0, Node.js implicitly pauses the stream buffer.
+      // React Ink's useInput hooks will silently fail to receive keystrokes if the stream remains paused.
+      if (process.stdin.isTTY) {
+        process.stdin.resume();
+      }
+
       await startInteractiveUI(
         config,
         settings,
diff --git a/packages/core/src/code_assist/oauth2.test.ts b/packages/core/src/code_assist/oauth2.test.ts
index afe35ce665..84a777820a 100644
--- a/packages/core/src/code_assist/oauth2.test.ts
+++ b/packages/core/src/code_assist/oauth2.test.ts
@@ -860,6 +860,85 @@ describe('oauth2', () => {
         global.setTimeout = originalSetTimeout;
       });
 
+      it('should clear the authorization timeout immediately upon successful web login to prevent memory leaks', async () => {
+        const mockAuthUrl = 'https://example.com/auth';
+        const mockCode = 'test-code';
+        const mockState = 'test-state';
+
+        const mockOAuth2Client = {
+          generateAuthUrl: vi.fn().mockReturnValue(mockAuthUrl),
+          getToken: vi.fn().mockResolvedValue({
+            tokens: {
+              access_token: 'test-token',
+              refresh_token: 'test-refresh',
+            },
+          }),
+          setCredentials: vi.fn().mockImplementation(function (
+            this: { credentials?: unknown },
+            creds: unknown,
+          ) {
+            this.credentials = creds;
+          }),
+          getAccessToken: vi.fn().mockResolvedValue({ token: 'test-token' }),
+          on: vi.fn(),
+          credentials: {},
+        } as unknown as OAuth2Client;
+        vi.mocked(OAuth2Client).mockImplementation(() => mockOAuth2Client);
+
+        vi.spyOn(crypto, 'randomBytes').mockReturnValue(mockState as never);
+        vi.mocked(open).mockImplementation(
+          async () => ({ on: vi.fn() }) as never,
+        );
+
+        let requestCallback!: http.RequestListener;
+        let serverListeningCallback: (value: unknown) => void;
+        const serverListeningPromise = new Promise(
+          (resolve) => (serverListeningCallback = resolve),
+        );
+
+        const mockHttpServer = {
+          listen: vi.fn(
+            (_port: number, _host: string, callback?: () => void) => {
+              if (callback) callback();
+              serverListeningCallback(undefined);
+            },
+          ),
+          close: vi.fn(),
+          on: vi.fn(),
+          address: () => ({ port: 3000 }),
+        };
+        (http.createServer as Mock).mockImplementation((cb) => {
+          requestCallback = cb;
+          return mockHttpServer as unknown as http.Server;
+        });
+
+        const clearTimeoutSpy = vi.spyOn(global, 'clearTimeout');
+
+        const clientPromise = getOauthClient(
+          AuthType.LOGIN_WITH_GOOGLE,
+          mockConfig,
+        );
+        await serverListeningPromise;
+
+        const mockReq = {
+          url: `/oauth2callback?code=${mockCode}&state=${mockState}`,
+        } as http.IncomingMessage;
+        const mockRes = {
+          writeHead: vi.fn(),
+          end: vi.fn(),
+          on: vi.fn(),
+        } as unknown as http.ServerResponse;
+
+        // Trigger the successful server response
+        requestCallback(mockReq, mockRes);
+        await clientPromise;
+
+        // Verify that the watchdog timer was cleared correctly
+        expect(clearTimeoutSpy).toHaveBeenCalled();
+
+        clearTimeoutSpy.mockRestore();
+      });
+
       it('should handle OAuth callback errors with descriptive messages', async () => {
         const mockAuthUrl = 'https://example.com/auth';
         const mockOAuth2Client = {
diff --git a/packages/core/src/code_assist/oauth2.ts b/packages/core/src/code_assist/oauth2.ts
index e238a4a860..0ae523dc94 100644
--- a/packages/core/src/code_assist/oauth2.ts
+++ b/packages/core/src/code_assist/oauth2.ts
@@ -332,8 +332,9 @@ async function initOauthClient(
 
     // Add timeout to prevent infinite waiting when browser tab gets stuck
     const authTimeout = 5 * 60 * 1000; // 5 minutes timeout
+    let timeoutId: NodeJS.Timeout | undefined;
     const timeoutPromise = new Promise<never>((_, reject) => {
-      setTimeout(() => {
+      timeoutId = setTimeout(() => {
         reject(
           new FatalAuthenticationError(
             'Authentication timed out after 5 minutes. The browser tab may have gotten stuck in a loading state. ' +
@@ -371,6 +372,9 @@ async function initOauthClient(
         cancellationPromise,
       ]);
     } finally {
+      if (timeoutId) {
+        clearTimeout(timeoutId);
+      }
       if (sigIntHandler) {
         process.removeListener('SIGINT', sigIntHandler);
       }