CVE-2026-27937: October: Reflected XSS via DataTable Form Widget
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
Other sources
October is a Content Management System (CMS) and web platform. Prior to 3.7.16 and 4.1.16, a reflected Cross-Site Scripting (XSS) vulnerability was identified in the backend DataTable widget where a query parameter was rendered without proper output escaping. This vulnerability is fixed in 3.7.16 and 4.1.16.
— MITRE
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-27937?
CVE-2026-27937 is classified as a reflected Cross-Site Scripting (XSS) vulnerability which can allow attackers to execute arbitrary scripts in the context of the user's session.
How do I fix CVE-2026-27937?
To fix CVE-2026-27937, upgrade October CMS to version 3.7.16 or 4.1.16 or later.
Which versions of October CMS are affected by CVE-2026-27937?
CVE-2026-27937 affects October CMS versions prior to 3.7.16 and 4.1.16.
What impact does CVE-2026-27937 have on website security?
CVE-2026-27937 can lead to unauthorized script execution, potentially compromising user data and session integrity.
Is CVE-2026-27937 easy to exploit?
Yes, CVE-2026-27937 can be exploited with basic knowledge of XSS attacks, making it a significant security risk.