GHSA-gcqv-f29m-67grMediumCVSS 4.8

October Rain has Stored XSS via SVG Filter Bypass

Published
April 14, 2026
Last Modified
June 16, 2026

🔗 CVE IDs covered (1)

CVE-2026-25133 →

📋 Description

A stored cross-site scripting (XSS) vulnerability was identified in the SVG sanitization logic. The regex pattern used to strip on* event handler attributes could be bypassed using a crafted payload that exploits how the pattern matches attribute boundaries.

Impact

  • Stored XSS via malicious SVG files uploaded through the Media Manager
  • Could allow privilege escalation if a superuser views or embeds the malicious SVG
  • Requires authenticated backend access with media upload permissions (media.library.create)
  • SVG must be viewed or embedded in a page to trigger

Patches

The vulnerability has been patched in v3.7.14 and v4.1.10. All users are encouraged to upgrade to the latest patched version.

Workarounds

If upgrading immediately is not possible:

  • Disable SVG uploads by adding svg to the blocked extensions in media configuration
  • Set media.clean_vectors to true in configuration (enabled by default)

References

  • Reported by Pentest-Tools.com

🎯 Affected products2

  • composer/october/rain:>= 4.0.0, <= 4.1.9
  • composer/october/rain:<= 3.7.13

🔗 References (3)