diff --git a/common/changes/@microsoft/rush/bmiddha-azureauthhelpertrim_2025-10-01-20-20.json b/common/changes/@microsoft/rush/bmiddha-azureauthhelpertrim_2025-10-01-20-20.json
new file mode 100644
index 00000000000..15b40b3b3f2
--- /dev/null
+++ b/common/changes/@microsoft/rush/bmiddha-azureauthhelpertrim_2025-10-01-20-20.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@microsoft/rush",
+      "comment": "[rush-azure-storage-build-cache-plugin] Trim access token output in AdoCodespacesAuthCredential",
+      "type": "patch"
+    }
+  ],
+  "packageName": "@microsoft/rush"
+}
\ No newline at end of file
diff --git a/rush-plugins/rush-azure-storage-build-cache-plugin/src/AdoCodespacesAuthCredential.ts b/rush-plugins/rush-azure-storage-build-cache-plugin/src/AdoCodespacesAuthCredential.ts
index 8ca8b4c0bee..86b2acfca26 100644
--- a/rush-plugins/rush-azure-storage-build-cache-plugin/src/AdoCodespacesAuthCredential.ts
+++ b/rush-plugins/rush-azure-storage-build-cache-plugin/src/AdoCodespacesAuthCredential.ts
@@ -54,7 +54,10 @@ export class AdoCodespacesAuthCredential implements TokenCredential {
       }
       const azureAuthHelperExec: string = 'azure-auth-helper';
 
-      const token: string = Executable.spawnSync(azureAuthHelperExec, ['get-access-token', scope]).stdout;
+      const token: string = Executable.spawnSync(azureAuthHelperExec, [
+        'get-access-token',
+        scope
+      ]).stdout.trim();
 
       let expiresOnTimestamp: number;