Cross-site scripting in Grav CMS - CVE-2025-66311
Published: May 5, 2026
Vulnerability identifier: #VU130063
CSH Severity: Low
CVSS v4.0: 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/E:U/U:Clear
CVE-ID: CVE-2025-66311
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Grav CMS
Affected software:
Grav CMS
Grav CMS
Detailed vulnerability description
The vulnerability allows a remote user to execute arbitrary script in a user's browser.
The vulnerability exists due to cross-site scripting in the /admin/pages/[page] endpoint when processing page metadata and taxonomy parameters. A remote privileged user can submit a specially crafted POST request containing malicious script in data[header][metadata], data[header][taxonomy][category], or data[header][taxonomy][tag] to execute arbitrary script in a user's browser.
User interaction is required when the affected page is accessed or rendered in the administrative interface.
How to mitigate CVE-2025-66311
Install security update from vendor's website.