CVE-2023-49279: Umbraco CMS

Medium severity, CVSS 5.4. EPSS: 0.4% chance of exploitation in the next 30 days.

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 products

• Umbraco Umbraco CMS: from 7.0.0, before 7.15.11 (fixed in 7.15.11); from 8.0.0, before 8.18.9 (fixed in 8.18.9); from 10.0.0, before 10.7.0 (fixed in 10.7.0); from 11.0.0, before 11.5.0 (fixed in 11.5.0); from 12.0.0, before 12.2.0 (fixed in 12.2.0)

Published 2023-12-12. Last modified 2026-06-17.