CVE-2024-34071 is a medium-severity (CVSS 6.1) Open Redirect vulnerability in UmbracoCms.Core. A fix is available for UmbracoCms.Core — see the affected versions and patch details below.
Open Redirect Bypass Protection
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-2024-34071.
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
UmbracoCms.Core.NETUmbracoCms.Core.NETUmbracoCms.Core.NETUmbracoCms.Core.NETUmbraco.Cms.Web.BackOffice.NETUmbraco.Cms.Web.BackOffice.NETUmbraco.Cms.Web.BackOffice.NETUmbraco.Cms.Web.BackOfficeReal-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 CMS used by more than 730.000 websites. Umbraco has an endpoint that is vulnerable to open redirects. The endpoint is protected so it requires the user to be signed into backoffice before the vulnerable is exposed. This vulnerability has been patched in version(s) 8.18.14, 10.8.6, 12.3.10 and 13.3.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | UmbracoCms.Core | ≥ 8.18.5&&< 8.18.14 | 8.18.14dotnet add package UmbracoCms.Core --version 8.18.14 |
| .NETNuGet | UmbracoCms.Core | ≥ 10.5.0&&< 10.8.6 | 10.8.6dotnet add package UmbracoCms.Core --version 10.8.6 |
| .NETNuGet | UmbracoCms.Core | ≥ 12.0.0&&< 12.3.10 | 12.3.10dotnet add package UmbracoCms.Core --version 12.3.10 |
| .NETNuGet | UmbracoCms.Core | ≥ 13.0.0&&< 13.3.1 | 13.3.1dotnet add package UmbracoCms.Core --version 13.3.1 |
| .NETNuGet | Umbraco.Cms.Web.BackOffice | ≥ 8.18.5&&< 8.18.14 | 8.18.14dotnet add package Umbraco.Cms.Web.BackOffice --version 8.18.14 |
| .NETNuGet | Umbraco.Cms.Web.BackOffice | ≥ 10.5.0&&< 10.8.6 | 10.8.6dotnet add package Umbraco.Cms.Web.BackOffice --version 10.8.6 |
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 UmbracoCms.Core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update UmbracoCms.Core to 8.18.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-34071 is resolved across your whole dependency graph.
Workarounds
Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.
Frequently Asked Questions
Is CVE-2024-34071 in your dependencies?
Find it across NuGet, including transitive dependencies.