CVE-2025-67288: Umbraco CMS

Critical severity, CVSS 10.0. EPSS: 0.6% chance of exploitation in the next 30 days.

An arbitrary file upload vulnerability in Umbraco CMS v16.3.3 allows attackers to execute arbitrary code by uploading a crafted PDF file. NOTE: this is disputed by the Supplier because the responsibility for file validation (as shown in the documentation) belongs to the system administrator who is implementing Umbraco CMS in their environment, not to Umbraco CMS itself. The Supplier also states that PDF JavaScript runs in a completely isolated sandbox, not the browser's DOM context, which means that privilege boundaries would not be crossed, a related issue to CVE-2023-49279.

Affected products

• Umbraco Umbraco CMS: version 16.3.3 only

Published 2025-12-22. Last modified 2026-07-08.