CVE-2026-21720
CVE-2026-21720 · Unauthenticated DoS: avatar cache leaks goroutines when /avatar/:hash requests time out
This page contains facts from public vulnerability sources. Check the original advisory before updating.
Every uncached /avatar/:hash request spawns a goroutine that refreshes the Gravatar image. If the refresh sits in the 10-slot worker queue longer than three seconds, the handler times out and stops listening for the result, so that goroutine blocks forever trying to send on an unbuffered channel. Sustained traffic with random hashes keeps tripping this timeout, so goroutine count grows linearly, eventually exhausting memory and causing Grafana to crash on some systems.
CVSS 7.5 · High · EPSS 0.7% · Fix available
- Published
- Updated
Stack: system · applications
Affected products and versions
grafana/grafana-enterprise
- Versions
- ≥ 3.0.0, < 11.6.9: Affected (semver)
Update to 11.6.9
grafana/grafana-enterprise
- Versions
- ≥ 3.0.0, < 12.0.8: Affected (semver)
Update to 12.0.8
grafana/grafana-enterprise
- Versions
- ≥ 3.0.0, < 12.1.5: Affected (semver)
Update to 12.1.5
grafana/grafana
- Versions
- ≥ 3.0.0, < 11.6.9: Affected (semver)
Update to 11.6.9
grafana/grafana
- Versions
- ≥ 3.0.0, < 12.0.8: Affected (semver)
Update to 12.0.8
grafana/grafana
- Versions
- ≥ 3.0.0, < 12.1.5: Affected (semver)
Update to 12.1.5
grafana/grafana-enterprise
- Versions
- ≥ 3.0.0, < 12.2.3: Affected (semver)
Update to 12.2.3
grafana/grafana
- Versions
- ≥ 3.0.0, < 12.2.3: Affected (semver)
Update to 12.2.3
grafana/grafana-enterprise
- Versions
- ≥ 3.0.0, < 12.3.1: Affected (semver)
Update to 12.3.1
grafana/grafana
- Versions
- ≥ 3.0.0, < 12.3.1: Affected (semver)
Update to 12.3.1
grafana Ubuntu:16.04:LTS
- Versions
- 2.6.0+dfsg-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published