CVE-2026-21720
Fixed in a distro release EPSS <1%CVSS 7.5
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.
Products: grafana/grafana-enterprise, grafana/grafana, Red Hat Ceph Storage 7, Red Hat Ceph Storage 8, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Chainguard | grafana-11.4 | no fix |
| Chainguard | grafana-11.4 | 11.4.8-r3 |
| Chainguard | grafana-11.5 | 11.5.10-r2 |
| Chainguard | grafana-fips-11.5 | no fix |
| SUSE Linux Enterprise Module for Package Hub 15 SP7 | golang-github-prometheus-promu | 0.17.0-150000.3.30.1 |
| SUSE Linux Enterprise Module for Package Hub 15 SP7 | grafana | 11.6.11-150200.3.83.1 |
| SUSE Manager Client Tools 15 | dracut-saltboot | 1.1.0-150000.1.65.1 |
| SUSE Manager Client Tools 15 | golang-github-QubitProducts-exporter_exporter | 0.4.0-150000.1.21.1 |
| SUSE Manager Client Tools 15 | golang-github-boynux-squid_exporter | 1.13.0-150000.1.12.1 |
| SUSE Manager Client Tools 15 | golang-github-lusitaniae-apache_exporter | 1.0.10-150000.1.26.1 |
| SUSE Manager Client Tools 15 | golang-github-prometheus-prometheus | 3.5.0-150000.3.67.1 |
| SUSE Manager Client Tools 15 | grafana | 11.6.11-150000.1.90.1 |
| SUSE Manager Client Tools 15 | prometheus-blackbox_exporter | 0.26.0-150000.1.30.2 |
| SUSE Manager Client Tools 15 | spacecmd | 5.0.15-150000.3.142.1 |
| SUSE Manager Client Tools 15 | uyuni-tools | 0.1.38-150000.1.30.1 |
| SUSE Manager Client Tools for SLE Micro 5 | dracut-saltboot | 1.1.0-150000.1.65.1 |
| SUSE Manager Client Tools for SLE Micro 5 | golang-github-QubitProducts-exporter_exporter | 0.4.0-150000.1.21.1 |
| SUSE Manager Client Tools for SLE Micro 5 | prometheus-blackbox_exporter | 0.26.0-150000.1.30.2 |
| SUSE Manager Client Tools for SLE Micro 5 | uyuni-tools | 0.1.38-150000.1.30.1 |
| SUSE Multi Linux Manager Tools SLE-15 | golang-github-lusitaniae-apache_exporter | 1.0.10-150002.3.6.1 |
| SUSE Multi Linux Manager Tools SLE-15 | golang-github-prometheus-prometheus | 3.5.0-150002.3.8.1 |
| SUSE Multi Linux Manager Tools SLE-15 | grafana | 11.6.14+security01-150002.4.14.1 |
| SUSE Multi Linux Manager Tools SLE-15 | prometheus-blackbox_exporter | 0.26.0-150002.3.6.1 |
| SUSE Multi Linux Manager Tools SLE-15 | spacecmd | 5.1.13-150002.3.9.3 |
| SUSE Multi Linux Manager Tools SLE-15 | uyuni-tools | 5.1.26-150002.3.12.1 |
| SUSE Multi Linux Manager Tools SLE-Micro-5 | prometheus-blackbox_exporter | 0.26.0-150002.3.6.1 |
| SUSE Multi Linux Manager Tools SLE-Micro-5 | uyuni-tools | 5.1.26-150002.3.12.1 |
| Ubuntu 16.04 LTS | grafana | no fix |
| openSUSE Leap 15.6 | dracut-saltboot | 1.1.0-150000.1.65.1 |
| openSUSE Leap 15.6 | golang-github-QubitProducts-exporter_exporter | 0.4.0-150000.1.21.1 |
| openSUSE Leap 15.6 | golang-github-boynux-squid_exporter | 1.13.0-150000.1.12.1 |
| openSUSE Leap 15.6 | golang-github-lusitaniae-apache_exporter | 1.0.10-150000.1.26.1 |
| openSUSE Leap 15.6 | golang-github-prometheus-promu | 0.17.0-150000.3.30.1 |
| openSUSE Leap 15.6 | grafana | 11.6.11-150200.3.83.1 |
| openSUSE Leap 15.6 | prometheus-blackbox_exporter | 0.26.0-150000.1.30.2 |
| openSUSE Leap 15.6 | spacecmd | 5.0.15-150000.3.142.1 |
| openSUSE Tumbleweed | grafana | 11.6.14+security01-1.1 |