Improper Neutralization of Special Elements in Output Used by a Downstream Component in Craft CMS - CVE-2026-25498
Published: April 17, 2026
Vulnerability identifier: #VU126477
CSH Severity: Low
CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-25498
CWE-ID: CWE-74
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to execute arbitrary code.
The vulnerability exists due to improper input sanitization in assembleLayoutFromPost() in src/services/Fields.php when processing the user-supplied fieldLayout POST parameter and passing it to Craft::createObject(). A remote user can submit a malicious behavior configuration via the "as " syntax to execute arbitrary code.
The issue affects admin panel endpoints that call assembleLayoutFromPost(), and exploitation requires admin-level access.
Affected software
Craft CMS
How to mitigate CVE-2026-25498
Install security update from vendor's website.
Craft CMS - addressed in versions 4.16.18, 5.8.22