CVE-2026-21720
Published: Jan 27, 2026
Modified: May 13, 2026
CVSS v3.1
7.5
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.
| Vendor | Product | Versions |
|---|---|---|
Grafana | grafana/grafana-enterprise | affected 3.0.0 - < 11.6.9 |
Grafana | grafana/grafana-enterprise | affected 3.0.0 - < 12.0.8 |
Grafana | grafana/grafana-enterprise | affected 3.0.0 - < 12.1.5 |
Grafana | grafana/grafana | affected 3.0.0 - < 11.6.9 |
Grafana | grafana/grafana | affected 3.0.0 - < 12.0.8 |
Grafana | grafana/grafana | affected 3.0.0 - < 12.1.5 |
Grafana | grafana/grafana-enterprise | affected 3.0.0 - < 12.2.3 |
Grafana | grafana/grafana | affected 3.0.0 - < 12.2.3 |
Grafana | grafana/grafana-enterprise | affected 3.0.0 - < 12.3.1 |
Grafana | grafana/grafana | affected 3.0.0 - < 12.3.1 |
CVSS v3.1 Details
CVSS v3.1 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
References
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