Grav before 2.0.15 contains a stored cross-site scripting vulnerability in the detectXss() function where unpaired quotes in unquoted attribute values bypass event-handler detection. Authenticated editors can inject event handlers like onerror= that pass validation and execute in visitor browsers when page content is rendered.
https://www.vulncheck.com/advisories/grav-before-stored-xss-via-detectxss-quote-bypass
https://github.com/getgrav/grav/security/advisories/GHSA-vfmf-q6x9-cw96
Published: 2026-08-18
Updated: 2026-09-08
Base Score: 8.5
Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:N
Severity: High
Base Score: 8.7
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Severity: High
Base Score: 9.3
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N
Severity: Critical
EPSS: 0.00271