Umbraco has Stored XSS in UFM Rendering Pipeline via Permissive DOMPurify Attribute Filtering

Description An authenticated backoffice user with access to Settings can inject malicious HTML into property type descriptions. Due to an overly permissive attributeNameCheck configuration /.+/ in the UFM DOMPurify instance, event handler attributes such as onclick and onload, when used within...

CVE-2026-31833

Summary : CVE-2026-31833 affects Umbraco (ASP.NET CMS). From 16.2.0 up to but not including 16.5.1 and 17.2.2, an authenticated backoffice user with Settings access can inject malicious HTML into property type descriptions due to an overly permissive attributeNameCheck in the UFM DOMPurify instan...