UBUNTU-CVE-2026-21720

See a problem?
Please try reporting it to the source first.
Source
https://ubuntu.com/security/CVE-2026-21720
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-21720.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-21720
Upstream
Published
2026-01-27T09:15:00Z
Modified
2026-01-30T21:15:07.231520Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

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.

References

Affected packages

Ubuntu:16.04:LTS / grafana

Package

Name
grafana
Purl
pkg:deb/ubuntu/grafana@2.6.0+dfsg-1?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.6.0+dfsg-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grafana",
            "binary_version": "2.6.0+dfsg-1"
        },
        {
            "binary_name": "grafana-data",
            "binary_version": "2.6.0+dfsg-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-21720.json"