Cross-site scripting in Grav CMS - CVE-2025-66309
Published: May 5, 2026
Vulnerability identifier: #VU130061
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2025-66309
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to execute arbitrary script in the victim's browser.
The vulnerability exists due to cross-site scripting in the /admin/pages/[page] endpoint when handling the data[header][content][items] parameter. A remote privileged user can craft a malicious URL with a script payload to execute arbitrary script in the victim's browser.
User interaction is required when the crafted URL is accessed.
Affected software
Grav CMS
How to mitigate CVE-2025-66309
Install security update from vendor's website.
Grav CMS - update to 1.7.49