Security Advisory
CVE-2026-40254
CVE vulnerability detail — eXtreme Datacenter Security Operations
Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Versions prior to 3.25.0 have an off-by-one in the path traversal filter in `channels/drive/client/drive_file.c`. The `contains_dotdot()` function catches `../` and `..` mid-path but misses `..` when its the last component with no trailing separator. A rogue RDP server can read, list, or write files one directory above the clients shared folder through RDPDR requests. This requires the victim to connect with drive redirection enabled. Version 3.25.0 patches the issue.