GHSA-jj38-h5w5-mvpfLowCVSS 3.1

October CMS: Reflected XSS via DataTable Form Widget

Published
April 21, 2026
Last Modified
April 24, 2026

🔗 CVE IDs covered (1)

CVE-2026-27937 →

📋 Description

A reflected Cross-Site Scripting (XSS) vulnerability was identified in the backend DataTable widget where a query parameter was rendered without proper output escaping.

Impact

  • Reflected XSS only, no stored/persistent component
  • The backend URL prefix is customizable and must be known or guessed by the attacker
  • Requires an authenticated backend user to visit a crafted URL
  • No direct access is gained without social engineering

Patches

The vulnerability has been patched in v3.7.16 and v4.1.16. The affected parameter is now properly escaped. All users are encouraged to upgrade to the latest patched version.

Workarounds

  • Use a non-default backend URL prefix (recommended as standard practice)
  • Implement a Content Security Policy (CSP) for backend pages

🎯 Affected products2

  • composer/october/system:< 3.7.16
  • composer/october/system:>= 4.0.0, < 4.1.16

🔗 References (3)