Path traversal in Umbraco CMS - #VU158825
Published: November 3, 2026
Vulnerability identifier: #VU158825
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-22
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to bypass intended path restrictions as part of a chain that executes stored scripts in another back-office user's browser context.
The vulnerability exists due to improper restriction of pathnames in Umbraco CMS media management when handling media file information. A remote user can supply a crafted path through media updates and chain path traversal with stored cross-site scripting to execute scripts with the privileges of another back-office user who interacts with the affected media item.
Affected software
Umbraco CMS
Remediation
Install security update from vendor's website.
Umbraco CMS - addressed in versions 17.7.2, 18.2.2