Authorization bypass through user-controlled key in Umbraco CMS - #VU153365
Published: October 6, 2026
Vulnerability identifier: #VU153365
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-639
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to delete media files outside their authorized media library scope.
The vulnerability exists due to improper access control in Backoffice media management when handling media operations. A remote user can perform media operations affecting files outside their permitted start node to delete media files outside their authorized media library scope.
Exploitation requires a Backoffice account with access to the Media section.
Affected software
Umbraco CMS
Remediation
Install security update from vendor's website.
Umbraco CMS - addressed in versions 17.7.1, 18.2.1