Stored XSS via SVG File UploadGHSA-6xmx-85x3-4cv2
NONEGHSA-6xmx-85x3-4cv2 is a none-severity (CVSS 0) Cross-site Scripting (XSS) vulnerability in Umbraco.CMS. A fix is available for Umbraco.CMS — see the affected versions and patch details below.
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 GHSA-6xmx-85x3-4cv2.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
Umbraco.CMS.NETUmbraco.CMS.NETUmbraco.CMS.NETUmbraco.CMS.NETUmbraco.CMSReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
Umbraco is an ASP.NET content management system (CMS). Starting in version 7.0.0 and prior to versions 7.15.11, 8.18.9, 10.7.0, 11.5.0, and 12.2.0, a user with access to the backoffice can upload SVG files that include scripts. If the user can trick another user to load the media directly in a browser, the scripts can be executed. Versions 7.15.11, 8.18.9, 10.7.0, 11.5.0, and 12.2.0 contain a patch for this issue. Some workarounds are available. Implement the server side file validation or serve all media from an different host (e.g cdn) than where Umbraco is hosted.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Umbraco.CMS | ≥ 7.0.0&&< 7.15.11 | 7.15.11dotnet add package Umbraco.CMS --version 7.15.11 |
| .NETNuGet | Umbraco.CMS | ≥ 8.0.0&&< 8.18.9 | 8.18.9dotnet add package Umbraco.CMS --version 8.18.9 |
| .NETNuGet | Umbraco.CMS | ≥ 9.0.0&&< 10.7.0 | 10.7.0dotnet add package Umbraco.CMS --version 10.7.0 |
| .NETNuGet | Umbraco.CMS | ≥ 11.0.0&&< 11.5.0 | 11.5.0dotnet add package Umbraco.CMS --version 11.5.0 |
| .NETNuGet | Umbraco.CMS | ≥ 12.0.0&&< 12.2.0 | 12.2.0dotnet add package Umbraco.CMS --version 12.2.0 |
Affected Products
umbraco cmsumbracoDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Umbraco.CMS, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Umbraco.CMS to 7.15.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6xmx-85x3-4cv2 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is GHSA-6xmx-85x3-4cv2 in your dependencies?
Find it across NuGet, including transitive dependencies.