CVE-2026-27199 Werkzeug safe_join() allows Windows special device names

Werkzeug is a comprehensive WSGI web application library. Versions 3.1.5 and below, the safejoin function allows Windows device names as filenames if preceded by other path segments. This was previously reported as GHSA-hgf8-39gv-g3f2, but the added filtering failed to account for the fact that...

CVE-2025-66221 Werkzeug safe_join() allows Windows special device names

Werkzeug is a comprehensive WSGI web application library. Prior to version 3.1.4, Werkzeug's safejoin function allows path segments with Windows device names. On Windows, there are special device names such as CON, AUX, etc that are implicitly present and readable in every directory...