CVE-2026-25959: Freerdp

Critical severity, CVSS 9.8. EPSS: 0.9% chance of exploitation in the next 30 days.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_cliprdr_provide_data_` passes freed `pDstData` to `XChangeProperty` because the cliprdr channel thread calls `xf_cliprdr_server_format_data_response` which converts and uses the clipboard data without holding any lock, while the X11 event thread concurrently calls `xf_cliprdr_clear_cached_data` → `HashTable_Clear` which frees the same data via `xf_cached_data_free`, triggering a heap use after free. Version 3.23.0 fixes the issue.

Affected products

• Freerdp Freerdp: before 3.23.0 (fixed in 3.23.0)

Published 2026-02-25. Last modified 2026-06-17.