CVE-2026-25959

Description

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.

References

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-78xg-v4p2-4w3c

https://github.com/FreeRDP/FreeRDP/commit/d3e8b3b9365be96a4f11dda149d71b3287227d0a

https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L933

https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L2363

https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L2323-L2334

https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L2295

https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L200-L208

https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L1337-L1344

https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_cliprdr.c#L1229-L1243

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-8736

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

CVSS v4

EPSS