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