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.NET
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MEDIUM severity

CVE-2025-27602 — Umbraco.Cms.Web.Backoffice

MEDIUMFix: umbraco/Umbraco-CMS@5b54bed

CVE-2025-27602 is a medium-severity (CVSS 4.9) CWE-285 vulnerability in Umbraco.Cms.Web.Backoffice. A fix is available for Umbraco.Cms.Web.Backoffice — see the affected versions and patch details below.

Umbraco Allows a Restricted Editor User to Delete Media Item or Access Unauthorized Content

Also known asGHSA-wx5h-wqfq-v698
Published
Updated
Affected
2 pkgs
Patched
2 / 2
Exploits
None indexed
Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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-2025-27602.

EPSS Exploitation Probability

via FIRST.org ↗
0.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs23th percentile — riskier than 23% of all scored CVEsHighest risk
0.00%0.27%0.54%0.80%0.3%0.3%May 26Sep 26Nov 26

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

2 pkgs affected
.NETUmbraco.Cms.Web.Backoffice.NETUmbraco.Cms.Web.Backoffice

Real-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 a free and open source .NET content management system. In versions of Umbraco's web backoffice program prior to versions 10.8.9 and 13.7.1, via manipulation of backoffice API URLs, it's possible for authenticated backoffice users to retrieve or delete content or media held within folders the editor does not have access to. The issue is patched in versions 10.8.9 and 13.7.1. No known workarounds are available.

Affected Packages

2 total 2 fixed
EcosystemPackageVulnerable rangeFix
.NETNuGetUmbraco.Cms.Web.Backofficeall versions10.8.9dotnet add package Umbraco.Cms.Web.Backoffice --version 10.8.9
.NETNuGetUmbraco.Cms.Web.Backoffice≥ 11.0.0-rc1&&< 13.7.113.7.1dotnet add package Umbraco.Cms.Web.Backoffice --version 13.7.1

Affected Products

1 product · 2 configurations
Application
umbraco cmsumbraco
≥ 11.0.0 && < 13.7.1
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Umbraco.Cms.Web.Backoffice, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update Umbraco.Cms.Web.Backoffice to 10.8.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-27602 is resolved across your whole dependency graph.

  3. Workarounds

    Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

Umbraco is a free and open source .NET content management system. In versions of Umbraco's web backoffice program prior to versions 10.8.9 and 13.7.1, via manipulation of backoffice API URLs, it's possible for authenticated backoffice users to retrieve or delete content or media held within folders the editor does not have access to. The issue is patched in versions 10.8.9 and 13.7.1. No known workarounds are available.
O3 Security · Impact-Aware SCA

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CVE-2025-27602: Umbraco.Cms.Web — Fixed in 10.8.9