CVE-2026-21720
high
Grafana CVSS v3 Base Score
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score
0.0%
Exploitation probability in 30 days
Top 94% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
None
Availability
High
Published: January 27, 2026 (107 days ago)
Last Modified: April 24, 2026
Vendor: Grafana
Source: MITRE
Vulnerability Report
Generated by CyberWatcher
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
Grafana grafana/grafana-enterpriseGrafana grafana/grafana