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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Grafana | grafana/grafana-enterprise | 3.0.0 – < 11.6.9, 3.0.0 – < 12.0.8, 3.0.0 – < 12.1.5, 3.0.0 – < 12.2.3, 3.0.0 – < 12.3.1 | 11.6.9 |
| Grafana | grafana/grafana | 3.0.0 – < 11.6.9, 3.0.0 – < 12.0.8, 3.0.0 – < 12.1.5, 3.0.0 – < 12.2.3, 3.0.0 – < 12.3.1 | 11.6.9 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | grafana | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | golang-github-prometheus-promu | 0.17.0-150000.3.30.1 | SUSE-SU-2026:1013-1 |
| SLES 15 SP7 | grafana | 11.6.11-150200.3.83.1 | SUSE-SU-2026:1037-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Multi Linux Manager Tools SLE-Micro-5 | prometheus-blackbox_exporter | 0.26.0-150002.3.6.1 | SUSE-SU-2026:1524-1 |
| SUSE Multi Linux Manager Tools SLE-Micro-5 | uyuni-tools | 5.1.26-150002.3.12.1 | SUSE-SU-2026:1524-1 |
| SUSE Multi Linux Manager Tools SLE-15 | golang-github-lusitaniae-apache_exporter | 1.0.10-150002.3.6.1 | SUSE-SU-2026:1524-1 |
| SUSE Multi Linux Manager Tools SLE-15 | golang-github-prometheus-prometheus | 3.5.0-150002.3.8.1 | SUSE-SU-2026:1524-1 |
| SUSE Multi Linux Manager Tools SLE-15 | grafana | 11.6.14+security01-150002.4.14.1 | SUSE-SU-2026:1524-1 |
| SUSE Multi Linux Manager Tools SLE-15 | prometheus-blackbox_exporter | 0.26.0-150002.3.6.1 | SUSE-SU-2026:1524-1 |
| SUSE Multi Linux Manager Tools SLE-15 | spacecmd | 5.1.13-150002.3.9.3 | SUSE-SU-2026:1524-1 |
| SUSE Multi Linux Manager Tools SLE-15 | uyuni-tools | 5.1.26-150002.3.12.1 | SUSE-SU-2026:1524-1 |
| SUSE Manager Client Tools for SLE Micro 5 | dracut-saltboot | 1.1.0-150000.1.65.1 | SUSE-SU-2026:1013-1 |
| SUSE Manager Client Tools for SLE Micro 5 | golang-github-QubitProducts-exporter_exporter | 0.4.0-150000.1.21.1 | SUSE-SU-2026:1013-1 |
| SUSE Manager Client Tools for SLE Micro 5 | prometheus-blackbox_exporter | 0.26.0-150000.1.30.2 | SUSE-SU-2026:1013-1 |
| SUSE Manager Client Tools for SLE Micro 5 | uyuni-tools | 0.1.38-150000.1.30.1 | SUSE-SU-2026:1013-1 |
| SUSE Manager Client Tools 15 | dracut-saltboot | 1.1.0-150000.1.65.1 | SUSE-SU-2026:1013-1 |
| SUSE Manager Client Tools 15 | golang-github-QubitProducts-exporter_exporter | 0.4.0-150000.1.21.1 | SUSE-SU-2026:1013-1 |
| SUSE Manager Client Tools 15 | golang-github-boynux-squid_exporter | 1.13.0-150000.1.12.1 | SUSE-SU-2026:1013-1 |
| SUSE Manager Client Tools 15 | golang-github-lusitaniae-apache_exporter | 1.0.10-150000.1.26.1 | SUSE-SU-2026:1013-1 |
| SUSE Manager Client Tools 15 | golang-github-prometheus-prometheus | 3.5.0-150000.3.67.1 | SUSE-SU-2026:1013-1 |
| SUSE Manager Client Tools 15 | grafana | 11.6.11-150000.1.90.1 | SUSE-SU-2026:1013-1 |
| SUSE Manager Client Tools 15 | prometheus-blackbox_exporter | 0.26.0-150000.1.30.2 | SUSE-SU-2026:1013-1 |
| SUSE Manager Client Tools 15 | spacecmd | 5.0.15-150000.3.142.1 | SUSE-SU-2026:1013-1 |
| SUSE Manager Client Tools 15 | uyuni-tools | 0.1.38-150000.1.30.1 | SUSE-SU-2026:1013-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | grafana | 11.6.14+security01-1.1 | openSUSE-SU-2026:10601-1 |
| openSUSE Leap 15.6 | dracut-saltboot | 1.1.0-150000.1.65.1 | SUSE-SU-2026:1013-1 |
| openSUSE Leap 15.6 | golang-github-QubitProducts-exporter_exporter | 0.4.0-150000.1.21.1 | SUSE-SU-2026:1013-1 |
| openSUSE Leap 15.6 | golang-github-boynux-squid_exporter | 1.13.0-150000.1.12.1 | SUSE-SU-2026:1013-1 |
| openSUSE Leap 15.6 | golang-github-lusitaniae-apache_exporter | 1.0.10-150000.1.26.1 | SUSE-SU-2026:1013-1 |
| openSUSE Leap 15.6 | golang-github-prometheus-promu | 0.17.0-150000.3.30.1 | SUSE-SU-2026:1013-1 |
| openSUSE Leap 15.6 | grafana | 11.6.11-150200.3.83.1 | SUSE-SU-2026:1037-1 |
| openSUSE Leap 15.6 | prometheus-blackbox_exporter | 0.26.0-150000.1.30.2 | SUSE-SU-2026:1013-1 |
| openSUSE Leap 15.6 | spacecmd | 5.0.15-150000.3.142.1 | SUSE-SU-2026:1013-1 |
Advisories 5
- WID-SEC-2026-0224 Grafana: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 8, 2026
- openSUSE-SU-2026:10601-1 grafana-11.6.14+security01-1.1 on GA media SUSE / openSUSE Security Updates · Apr 23, 2026
- SUSE-SU-2026:1524-1 Security update 5.1.3 for Multi-Linux Manager Client Tools SUSE / openSUSE Security Updates · Apr 22, 2026
- SUSE-SU-2026:1037-1 Security update for grafana SUSE / openSUSE Security Updates · Mar 26, 2026
- SUSE-SU-2026:1013-1 Security update 5.0.7 for Multi-Linux Manager Client Tools SUSE / openSUSE Security Updates · Mar 26, 2026
References
- https://grafana.com/security/security-advisories/cve-2026-21720 vendor-advisory