CVE-2026-21720

Name
CVE-2026-21720
Description
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.
NVD Severity
unknown
Other trackers
CVE, NVD, CERT, CVE Details, CIRCL, Arch Linux, Debian, Red Hat, Ubuntu, Gentoo, SUSE (Bugzilla), SUSE (CVE), Mageia
Mailing lists
oss-security, full-disclosure, bugtraq
Exploits
Exploit DB, Metasploit
Forges
GitHub (code, issues), Aports (code, issues)

References

Type URI
security@grafana.com https://grafana.com/security/security-advisories/CVE-2026-21720

Match rules

CPE URI Source package Min version Max version
cpe:2.3:a:grafana:grafana:*:*:*:*:-:*:*:* grafana >= 3.0.0 < 11.6.9
cpe:2.3:a:grafana:grafana:*:*:*:*:-:*:*:* grafana >= 12.0.0 < 12.0.8
cpe:2.3:a:grafana:grafana:*:*:*:*:-:*:*:* grafana >= 12.1.0 < 12.1.5
cpe:2.3:a:grafana:grafana:*:*:*:*:-:*:*:* grafana >= 12.2.0 < 12.2.3
cpe:2.3:a:grafana:grafana:12.3.0:*:*:*:-:*:*:* grafana == None == 12.3.0

Vulnerable and fixed packages

Source package Branch Version Maintainer Status
grafana edge-community 12.2.1-r4 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 12.2.1-r3 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 12.2.1-r2 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 12.2.1-r1 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 12.2.1-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 12.1.1-r2 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 12.1.1-r1 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 12.1.1-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 12.0.2-r2 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 12.0.2-r1 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 12.0.2-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 12.0.1-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 12.0.0-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 11.6.1-r0 None possibly vulnerable
grafana edge-community 11.6.0-r2 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 11.6.0-r1 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 11.6.0-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 11.5.2-r1 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 11.5.2-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 11.5.1-r1 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 11.5.1-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 11.5.0-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 11.4.0-r1 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 11.4.0-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 11.3.2-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 11.3.1-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 11.1.4-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 9.1.2-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 9.0.3-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 8.5.3-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 8.3.6-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 8.3.4-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 8.3.2-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 8.3.1-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 8.2.4-r0 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana edge-community 7.4.5-r0 None possibly vulnerable
grafana edge-community 7.0.2-r0 None possibly vulnerable
grafana edge-community 6.3.4-r0 None possibly vulnerable
grafana 3.23-community 12.2.1-r4 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana 3.23-community 12.2.1-r3 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana 3.23-community 12.2.1-r2 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable
grafana 3.23-community 12.2.1-r1 Konstantin Kulikov <k.kulikov2@gmail.com> possibly vulnerable