Unrated severityOSV Advisory· Published Jan 27, 2026· Updated Apr 24, 2026
Unauthenticated DoS: avatar cache leaks goroutines when /avatar/:hash requests time out
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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected products
37- osv-coords35 versionspkg:apk/chainguard/grafana-11.5pkg:apk/wolfi/grafana-11.5pkg:bitnami/grafanapkg:rpm/opensuse/dracut-saltboot&distro=openSUSE%20Leap%2015.6pkg:rpm/opensuse/golang-github-boynux-squid_exporter&distro=openSUSE%20Leap%2015.6pkg:rpm/opensuse/golang-github-lusitaniae-apache_exporter&distro=openSUSE%20Leap%2015.6pkg:rpm/opensuse/golang-github-prometheus-promu&distro=openSUSE%20Leap%2015.6pkg:rpm/opensuse/golang-github-QubitProducts-exporter_exporter&distro=openSUSE%20Leap%2015.6pkg:rpm/opensuse/grafana&distro=openSUSE%20Leap%2015.6pkg:rpm/opensuse/grafana&distro=openSUSE%20Tumbleweedpkg:rpm/opensuse/prometheus-blackbox_exporter&distro=openSUSE%20Leap%2015.6pkg:rpm/opensuse/spacecmd&distro=openSUSE%20Leap%2015.6pkg:rpm/suse/dracut-saltboot&distro=SUSE%20Manager%20Client%20Tools%2015pkg:rpm/suse/dracut-saltboot&distro=SUSE%20Manager%20Client%20Tools%20for%20SLE%20Micro%205pkg:rpm/suse/golang-github-boynux-squid_exporter&distro=SUSE%20Manager%20Client%20Tools%2015pkg:rpm/suse/golang-github-lusitaniae-apache_exporter&distro=SUSE%20Manager%20Client%20Tools%2015pkg:rpm/suse/golang-github-lusitaniae-apache_exporter&distro=SUSE%20Multi%20Linux%20Manager%20Tools%20SLE-15pkg:rpm/suse/golang-github-prometheus-prometheus&distro=SUSE%20Manager%20Client%20Tools%2015pkg:rpm/suse/golang-github-prometheus-prometheus&distro=SUSE%20Multi%20Linux%20Manager%20Tools%20SLE-15pkg:rpm/suse/golang-github-prometheus-promu&distro=SUSE%20Linux%20Enterprise%20Module%20for%20Package%20Hub%2015%20SP7pkg:rpm/suse/golang-github-QubitProducts-exporter_exporter&distro=SUSE%20Manager%20Client%20Tools%2015pkg:rpm/suse/golang-github-QubitProducts-exporter_exporter&distro=SUSE%20Manager%20Client%20Tools%20for%20SLE%20Micro%205pkg:rpm/suse/grafana&distro=SUSE%20Linux%20Enterprise%20Module%20for%20Package%20Hub%2015%20SP7pkg:rpm/suse/grafana&distro=SUSE%20Manager%20Client%20Tools%2015pkg:rpm/suse/grafana&distro=SUSE%20Multi%20Linux%20Manager%20Tools%20SLE-15pkg:rpm/suse/prometheus-blackbox_exporter&distro=SUSE%20Manager%20Client%20Tools%2015pkg:rpm/suse/prometheus-blackbox_exporter&distro=SUSE%20Manager%20Client%20Tools%20for%20SLE%20Micro%205pkg:rpm/suse/prometheus-blackbox_exporter&distro=SUSE%20Multi%20Linux%20Manager%20Tools%20SLE-15pkg:rpm/suse/prometheus-blackbox_exporter&distro=SUSE%20Multi%20Linux%20Manager%20Tools%20SLE-Micro-5pkg:rpm/suse/spacecmd&distro=SUSE%20Manager%20Client%20Tools%2015pkg:rpm/suse/spacecmd&distro=SUSE%20Multi%20Linux%20Manager%20Tools%20SLE-15pkg:rpm/suse/uyuni-tools&distro=SUSE%20Manager%20Client%20Tools%2015pkg:rpm/suse/uyuni-tools&distro=SUSE%20Manager%20Client%20Tools%20for%20SLE%20Micro%205pkg:rpm/suse/uyuni-tools&distro=SUSE%20Multi%20Linux%20Manager%20Tools%20SLE-15pkg:rpm/suse/uyuni-tools&distro=SUSE%20Multi%20Linux%20Manager%20Tools%20SLE-Micro-5
< 11.5.10-r2+ 34 more
- (no CPE)range: < 11.5.10-r2
- (no CPE)range: < 11.5.10-r2
- (no CPE)range: >= 3.0.0, < 11.6.9
- (no CPE)range: < 1.1.0-150000.1.65.1
- (no CPE)range: < 1.13.0-150000.1.12.1
- (no CPE)range: < 1.0.10-150000.1.26.1
- (no CPE)range: < 0.17.0-150000.3.30.1
- (no CPE)range: < 0.4.0-150000.1.21.1
- (no CPE)range: < 11.6.11-150200.3.83.1
- (no CPE)range: < 11.6.14+security01-1.1
- (no CPE)range: < 0.26.0-150000.1.30.2
- (no CPE)range: < 5.0.15-150000.3.142.1
- (no CPE)range: < 1.1.0-150000.1.65.1
- (no CPE)range: < 1.1.0-150000.1.65.1
- (no CPE)range: < 1.13.0-150000.1.12.1
- (no CPE)range: < 1.0.10-150000.1.26.1
- (no CPE)range: < 1.0.10-150002.3.6.1
- (no CPE)range: < 3.5.0-150000.3.67.1
- (no CPE)range: < 3.5.0-150002.3.8.1
- (no CPE)range: < 0.17.0-150000.3.30.1
- (no CPE)range: < 0.4.0-150000.1.21.1
- (no CPE)range: < 0.4.0-150000.1.21.1
- (no CPE)range: < 11.6.11-150200.3.83.1
- (no CPE)range: < 11.6.11-150000.1.90.1
- (no CPE)range: < 11.6.14+security01-150002.4.14.1
- (no CPE)range: < 0.26.0-150000.1.30.2
- (no CPE)range: < 0.26.0-150000.1.30.2
- (no CPE)range: < 0.26.0-150002.3.6.1
- (no CPE)range: < 0.26.0-150002.3.6.1
- (no CPE)range: < 5.0.15-150000.3.142.1
- (no CPE)range: < 5.1.13-150002.3.9.3
- (no CPE)range: < 0.1.38-150000.1.30.1
- (no CPE)range: < 0.1.38-150000.1.30.1
- (no CPE)range: < 5.1.26-150002.3.12.1
- (no CPE)range: < 5.1.26-150002.3.12.1
Patches
Vulnerability mechanics
References
1- grafana.com/security/security-advisories/cve-2026-21720mitrevendor-advisory
News mentions
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