CVE-2025-24012 is a medium-severity (CVSS 4.6) Cross-site Scripting (XSS) vulnerability in @umbraco-cms/backoffice. A fix is available for @umbraco-cms/backoffice — see the affected versions and patch details below.
Umbraco Backoffice Components Have XSS/HTML Injection Vulnerability
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-2025-24012.
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
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@umbraco-cms/backofficenpmDescription
Umbraco is a free and open source .NET content management system. Starting in version 14.0.0 and prior to versions 14.3.2 and 15.1.2, authenticated users are able to exploit a cross-site scripting vulnerability when viewing certain localized backoffice components. Versions 14.3.2 and 15.1.2 contain a patch.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @umbraco-cms/backoffice | ≥ 14.0.0&&< 14.3.2 | 14.3.2npm install @umbraco-cms/backoffice@14.3.2 |
| 📦npm | @umbraco-cms/backoffice | ≥ 15.0.0&&< 15.1.2 | 15.1.2npm install @umbraco-cms/backoffice@15.1.2 |
| .NETNuGet | Umbraco.Cms.StaticAssets | ≥ 14.0.0&&< 14.3.2 | 14.3.2dotnet add package Umbraco.Cms.StaticAssets --version 14.3.2 |
| .NETNuGet | Umbraco.Cms.StaticAssets | ≥ 15.0.0&&< 15.1.2 | 15.1.2dotnet add package Umbraco.Cms.StaticAssets --version 15.1.2 |
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/backoffice, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @umbraco-cms/backoffice to 14.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-24012 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 CVE-2025-24012 in your dependencies?
Find it across npm, NuGet, including transitive dependencies.