What happened
Only self-managed Grafana instances with Auth Proxy authentication and identity caching enabled (sync_ttl greater than zero) are affected. The Auth Proxy cache key concatenated the username and forwarded identity attributes without a delimiter, so distinct identities could collide on one key. An authenticated user who shapes their own attributes to collide with a higher-privileged user's, while that user's cache entry is live, is authenticated as that user, up to Administrator (authentication bypass by spoofing).
Affected versions
Grafana Enterprise: 11.0.0 through 11.6.17 (semver); 12.0.0 through 12.2.11 (semver); 12.3.0 through 12.3.11 (semver); 12.4.0 through 12.4.9 (semver); 13.0.0 through 13.0.7 (semver); 13.1.0 through 13.1.4 (semver); 13.2.0 through 13.2.0 (semver) Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.
Public PoC references
No public PoC reference has passed the current publication threshold.