Grafana XSS via alert.generatorURL in external Alertmanager alerts
CVE-2026-17033 Published on August 24, 2026
CVE-2026-17033 CVE Record
An authenticated attacker with Editor access or alert.instances.external:write can submit an external Alertmanager alert containing a controlled generatorURL. The attacker is authorized to create the alert, but not to execute script in another user's Grafana session.
Grafana renders alert.generatorURL directly as the Alert Details See source LinkButton href without URL-scheme sanitization or a safe-protocol allowlist. The click interceptor's :// heuristic can be bypassed by placing :// inside a JavaScript comment. When a user with read access clicks See source, the browser executes attacker-controlled JavaScript in the Grafana origin with the clicking user's permissions.
Weakness Type
What is a XSS Vulnerability?
The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
CVE-2026-17033 has been classified to as a XSS vulnerability or weakness.
Products Associated with CVE-2026-17033
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Affected Versions
Grafana OSS:- Before and including 12.3.11 is affected.
- Version 12.4.0, <= 12.4.9 is affected.
- Version 13.0.0, <= 13.0.7 is affected.