Vulnerability · Published Apr 14, 2026 · Assigned by GitHub_M

CVE-2026-25133October CMS has Stored XSS via SVG Filter Bypass

Medium 4.8

In plain English

A medium-severity cross-site scripting in october from octobercms. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)4.8Medium

Exploit odds (30 days)0.2%top 87.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	october/rain	4.1.10	GHSA-gcqv-f29m-67gr
Packagist	october/rain	3.7.14	GHSA-gcqv-f29m-67gr

Affected products (as reported)

Vendor	Product	Versions
octobercms	october	< 3.7.14>= 4.0.0, < 4.1.10

Weakness: CWE-79 · 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

References

https://github.com/octobercms/october/security/advisories/GHSA-gcqv-f29m-67gr x_refsource_CONFIRM