Winter CMS has Stored Cross-site Scripting (XSS) in Asset Manager
Impact
Affected versions of Winter CMS allow users with access to the CMS Asset Manager were able to upload SVGs without automatic sanitization.
To actively exploit this security issue, an attacker would need access to the Backend with a user account with the following permission: cms.manage_assets
The Winter CMS maintainers strongly recommend that the cms.manage_assets permission only be reserved to trusted administrators and developers in general.
Patches
Sanitization of SVG assets is now applied automatically when uploading through the CMS Asset Manager.
This security issue has been fixed as of https://github.com/wintercms/winter/commit/8a7f74b004fcd19721764fc63af0cdb339d9fb65.
Workarounds
If users cannot upgrade, they may apply commit https://github.com/wintercms/winter/commit/8a7f74b004fcd19721764fc63af0cdb339d9fb65 to their Winter CMS installation manually to resolve this issue.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | winter/wn-cms-module | < 1.2.10 | 1.2.10 |
References
- https://github.com/wintercms/winter/security/advisories/GHSA-m7gw-rffq-rxjm
- https://nvd.nist.gov/vuln/detail/CVE-2026-22254
- https://github.com/wintercms/winter/commit/8a7f74b004fcd19721764fc63af0cdb339d9fb65
- https://github.com/wintercms/winter
- https://github.com/wintercms/winter/releases/tag/v1.2.10
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:N/A:N- Weakness (CWE)
CWE-79- Platform
- Composer
- Package
winter/wn-cms-module- Disclosed
- 04.02.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-m7gw-rffq-rxjm - CC BY 4.0
Vulnerability history: winter/wn-cms-module
All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 3
- First → latest
- 12.2024 08.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 1
- Medium 1
- Low 1
Disclosures per year
- 2024: 1
- 2025: 0
- 2026: 2
-
Winter CMS has Stored Cross-site Scripting (XSS) in Asset Manager this entry
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