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.NET
.NET NuGet
Not in CISA KEV
MEDIUM severity

CVE-2024-48926 — Umbraco.CMS

MEDIUM

CVE-2024-48926 is a medium-severity (CVSS 4.2) CWE-613 vulnerability in Umbraco.CMS. A fix is available for Umbraco.CMS — see the affected versions and patch details below.

Umbraco CMS logout page displayed before session expiration

Also known asGHSA-fp6q-gccw-7qqm
Published
Updated
Affected
3 pkgs
Patched
3 / 3
Exploits
None indexed
Exploitation data as of Nov 4, 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-2024-48926.

EPSS Exploitation Probability

via FIRST.org ↗
0.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs19th percentile — riskier than 19% of all scored CVEsHighest risk
0.00%0.29%0.58%0.88%0.4%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

3 pkgs affected
.NETUmbraco.CMS.NETUmbraco.CMS.NETUmbracoCMS

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, a free and open source .NET content management system, has an insufficient session expiration issue in versions on the 13.x branch prior to 13.5.2, 10.x prior to 10.8.7, and 8.x prior to 8.18.15. The Backoffice displays the logout page with a session timeout message before the server session has fully expired, causing users to believe they have been logged out approximately 30 seconds before they actually are. Versions 13.5.2, 10.8,7, and 8.18.15 contain a patch for the issue.

Affected Packages

3 total 3 fixed
EcosystemPackageVulnerable rangeFix
.NETNuGetUmbraco.CMS≥ 13.0.0&&< 13.5.213.5.2dotnet add package Umbraco.CMS --version 13.5.2
.NETNuGetUmbraco.CMS≥ 10.0.0&&< 10.8.710.8.7dotnet add package Umbraco.CMS --version 10.8.7
.NETNuGetUmbracoCMS≥ 8.0.0&&< 8.18.158.18.15dotnet add package UmbracoCMS --version 8.18.15

Affected Products

1 product · 3 configurations
Application
umbraco cmsumbraco
≥ 13.0 && < 13.5.2
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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update Umbraco.CMS to 13.5.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-48926 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, a free and open source .NET content management system, has an insufficient session expiration issue in versions on the 13.x branch prior to 13.5.2, 10.x prior to 10.8.7, and 8.x prior to 8.18.15. The Backoffice displays the logout page with a session timeout message before the server session has fully expired, causing users to believe they have been logged out approximately 30 seconds before they actually are. Versions 13.5.2, 10.8,7, and 8.18.15 contain a patch for the issue.
O3 Security · Impact-Aware SCA

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CVE-2024-48926: Umbraco.CMS — Fixed in 13.5.2