CVE-2026-12715 Overview
CVE-2026-12715 is a missing authorization vulnerability [CWE-862] in Google Cloud Firebase Studio. The flaw allows authenticated attackers to download other users' deployed source code by issuing unauthorized Google Cloud Storage (GCS) URL signing requests. Successful exploitation exposes proprietary application code and any sensitive data embedded in deployed artifacts. Google patched the issue on 15 April 2026 as a server-side fix. Customers do not need to take any action to remediate the vulnerability.
Critical Impact
Authenticated attackers could retrieve other tenants' deployed source code and sensitive data from Firebase Studio via forged GCS signed URL requests, resulting in cross-tenant confidentiality loss.
Affected Products
- Google Cloud Firebase Studio (versions prior to the 2026-04-15 server-side patch)
- Deployments hosted on Google Cloud Platform
- Firebase Studio projects storing source code artifacts in Google Cloud Storage
Discovery Timeline
- 2026-04-15 - Google Cloud releases the server-side patch for Firebase Studio
- 2026-07-17 - CVE-2026-12715 published to NVD
- 2026-07-17 - Last updated in NVD database
Technical Details for CVE-2026-12715
Vulnerability Analysis
Firebase Studio is a cloud-based development environment that stores deployed source code and build artifacts in Google Cloud Storage buckets. The service exposes an endpoint that returns pre-signed GCS URLs so authorized users can download their own artifacts. The vulnerability stems from a missing authorization check on this signing endpoint. An authenticated attacker could request a signed URL for an object owned by a different tenant and receive a valid short-lived download link. The exploit path required only low privileges and no user interaction. Because signed URLs bypass GCS bucket-level access controls once issued, the attacker could then retrieve the target object directly. The resulting exposure affected confidentiality of source code, embedded secrets, configuration files, and any data bundled into deployed artifacts.
Root Cause
The root cause is a broken access control pattern [CWE-862]. The URL signing service authenticated the caller but failed to verify that the caller owned or had permission to access the requested GCS object path. Ownership validation was assumed at an upstream layer that was not enforced on this specific request handler.
Attack Vector
Exploitation occurred over the network against the Firebase Studio API. An attacker with a valid Firebase Studio account submitted a signing request referencing another tenant's object path. The service returned a signed GCS URL, which the attacker fetched to download the target artifact. No memory corruption, code execution, or client-side interaction was required.
No public proof-of-concept code is available. See the Google Cloud Support Bulletin GCP-2026-043 for vendor technical details.
Detection Methods for CVE-2026-12715
Indicators of Compromise
- Unexpected GCS signed URL generation requests referencing object paths outside the requesting user's projects.
- Anomalous download activity against Firebase Studio artifact buckets from IP addresses not associated with the project owner.
- Audit log entries showing storage.objects.get or signed URL retrievals for cross-tenant object paths prior to 15 April 2026.
Detection Strategies
- Review Google Cloud Audit Logs for Firebase Studio signing API calls where the caller identity does not match the target project owner.
- Correlate SignBlob and iamcredentials.googleapis.com events with subsequent GCS GetObject requests to identify suspicious URL usage chains.
- Baseline normal signed-URL request volumes per identity and alert on statistical outliers before the patch date.
Monitoring Recommendations
- Enable Data Access audit logs for Cloud Storage buckets backing Firebase Studio deployments.
- Forward GCP audit logs to a centralized analytics platform for retroactive review of pre-patch activity.
- Monitor for downloads of build artifacts from unusual geographic locations or service accounts.
How to Mitigate CVE-2026-12715
Immediate Actions Required
- No customer action is required. Google applied the fix server-side on 15 April 2026 across the Firebase Studio managed service.
- Review historical audit logs covering the window before 15 April 2026 for evidence of unauthorized signed URL requests.
- Rotate any secrets, API keys, or credentials that may have been embedded in Firebase Studio deployed artifacts as a precaution.
Patch Information
Google Cloud remediated CVE-2026-12715 on 15 April 2026 through a service-side update to the Firebase Studio URL signing component. Because Firebase Studio is a managed platform-as-a-service offering, the patch was deployed automatically to all tenants without requiring version upgrades or customer intervention. Full details are documented in the Google Cloud Support Bulletin GCP-2026-043.
Workarounds
- No workaround is required post-patch. All Firebase Studio tenants receive the fix automatically.
- For defense in depth, restrict Firebase Studio access using Google Cloud IAM conditions and organization policies.
- Avoid embedding long-lived secrets in source code deployed through Firebase Studio; use Secret Manager instead.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
