CVE-2026-24906

MEDIUM

October CMS has Stored XSS in its Backend Editor Markup Classes

Title source: cna
STIX 2.1

Description

October is a Content Management System (CMS) and web platform. Versions prior to 3.7.14 and 4.1.10 contain a Stored Cross-Site Scripting (XSS) vulnerability in the Backend Editor Settings. The Markup Classes fields (used for paragraph styles, inline styles, table styles, etc.) did not sanitize input to valid CSS class name characters. Malicious values were rendered unsanitized in Froala editor dropdown menus, allowing JavaScript execution when any user opened a RichEditor. Exploitation could lead to privilege escalation if a superuser opens any RichEditor during routine content editing (e.g., editing a blog post), and requires authenticated backend access with editor settings permissions. This issue has been fixed in versions 3.7.14 and 4.1.10. To workaround this issue, restrict editor settings permissions to fully trusted administrators only

References (1)

Core 1
Core References

Scores

CVSS v3 5.4
EPSS 0.0025
EPSS Percentile 16.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-79
Status published
Products (4)
october/system 4.0.0 - 4.1.10Packagist
octobercms/october < 3.7.13
octobercms/october < 3.7.14
octobercms/october >= 4.0.0, < 4.1.10
Published Apr 14, 2026
Tracked Since Apr 14, 2026