CVE-2026-31859

Craft is a content management system (CMS). The fix for CVE-2025-35939 in craftcms/cms introduced a strip_tags() call in src/web/User.php to sanitize return URLs before they are stored in the session. However, strip_tags() only removes HTML tags (angle brackets) -- it does not inspect or filter URL schemes. Payloads like javascript:alert(document.cookie) contain no HTML tags and pass through strip_tags() completely unmodified, enabling reflected XSS when the return URL is rendered in an href attribute. This vulnerability is fixed in 5.9.7 and 4.17.3.
References
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:craftcms:craft_cms:*:*:*:*:*:*:*:*
cpe:2.3:a:craftcms:craft_cms:*:*:*:*:*:*:*:*

History

17 Mar 2026, 14:03

Type Values Removed Values Added
References () https://github.com/craftcms/cms/security/advisories/GHSA-fvwq-45qv-xvhv - () https://github.com/craftcms/cms/security/advisories/GHSA-fvwq-45qv-xvhv - Patch, Vendor Advisory
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 6.1
First Time Craftcms
Craftcms craft Cms
CPE cpe:2.3:a:craftcms:craft_cms:*:*:*:*:*:*:*:*
Summary
  • (es) Craft es un sistema de gestión de contenidos (CMS). La corrección para CVE-2025-35939 en craftcms/cms introdujo una llamada a strip_tags() en src/web/User.php para depurar las URL de retorno antes de que se almacenen en la sesión. Sin embargo, strip_tags() solo elimina las etiquetas HTML (corchetes angulares); no inspecciona ni filtra los esquemas de URL. Las cargas útiles como javascript:alert(document.cookie) no contienen etiquetas HTML y pasan por strip_tags() sin sufrir ninguna modificación, lo que permite un XSS reflejado cuando la URL de retorno se representa en un atributo href. Esta vulnerabilidad se ha corregido en las versiones 5.9.7 y 4.17.3.

11 Mar 2026, 18:16

Type Values Removed Values Added
New CVE

Information

Published : 2026-03-11 18:16

Updated : 2026-03-17 14:03


NVD link : CVE-2026-31859

Mitre link : CVE-2026-31859

CVE.ORG link : CVE-2026-31859


JSON object : View

Products Affected

craftcms

  • craft_cms
CWE
CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CWE-116

Improper Encoding or Escaping of Output