Description
Grav versions from 1.5.2 through 2.0.12 contain a stored cross-site scripting vulnerability in the Security::detectXss() function (system/src/Grav/Common/Security.php). The event-handler scan is anchored at `<` and uses `[^>]*?`, which cannot cross the first literal `>`; when a `>` appears inside a quoted attribute value the browser keeps the tag open and parses a subsequent event handler (e.g. onerror), so the detector and browser disagree. A page editor without admin.super privileges can save page content such as `<img src=x title=">" onerror=alert(document.domain)>`, which is accepted, stored, and executed in the site origin when any visitor (including unauthenticated users) views the page. Fixed in 2.0.13.
Metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:NWeakness enumeration
Affected software
No affected versions have been published.
Timeline
- Published
- Aug 14, 2026
- Last modified
- Oct 8, 2026
- NVD status
- Deferred