CVE-2026-45454 SharePoint Upload.aspx RootFolder Path Traversal to masterpage
Detects attempts to upload files to the SharePoint master page gallery using a POST request. This activity can be indicative of an attacker attempting to establish persistence or deface the SharePoint site by modifying its core components. The rule specifically looks for requests to '_layouts/15/Upload.aspx' or '_layouts/Upload.aspx' with 'RootFolder' and 'List' parameters containing '_catalogs/masterpage' or directory traversal sequences ('../').
Microsoft Sentinel (KQL)
