CVE-2026-22254 is a none-severity (CVSS 0) Cross-site Scripting (XSS) vulnerability in winter/wn-cms-module. A fix is available for winter/wn-cms-module — see the affected versions and patch details below.
Winter Affected by Stored Cross-Site Scripting (XSS) in Asset Manager
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-22254.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-22254 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
winter/wn-cms-moduleReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | winter/wn-cms-module | all versions | 1.2.10composer require winter/wn-cms-module:^1.2.10 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for winter/wn-cms-module, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update winter/wn-cms-module to 1.2.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-22254 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-22254 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-22254. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-22254 in your dependencies?
O3 Security finds CVE-2026-22254 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.