CVE-2026-25133CWE-79

October CMS has Stored XSS via SVG Filter Bypass

Medium · published April 14, 2026

CVSS v4.0
4.8
EPSS
0%
Percentile
11.5
In the wild
Unconfirmed
What it is

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 SVG sanitization logic. The regex pattern used to strip event handler attributes (such as onclick or onload) could be bypassed using a crafted payload that exploits how the pattern matches attribute boundaries, allowing malicious SVG files to be uploaded through the Media Manager with embedded JavaScript. Exploitation could lead to privilege escalation if a superuser views or embeds the malicious SVG, and requires authenticated backend access with media upload permissions. The SVG must be viewed or embedded in a page for the payload to trigger. This issue has been fixed in versions 3.7.14 and 4.1.10.

The record
Technical detail
CVSS v4.0
4.8 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
EPSS
0.00217 · 11.5th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-04-14T20:47Z
EPSS history
Timeline
  • 14 APR 20:47Z
    October CMS has Stored XSS via SVG Filter Bypass
    cvelistv5