CVE-2026-26986 PUBLISHED

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, rail_window_free dereferences a freed xfAppWindow pointer during HashTable_Free cleanup because xf_rail_window_common calls free(appWindow) on title allocation failure without first removing the entry from the railWindows hash table, leaving a dangling pointer that is freed again on disconnect. Version 3.23.0 fixes the vulnerability.

• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-crqx-g6x5-rx47
• https://github.com/FreeRDP/FreeRDP/commit/b4f0f0a18fe53aa8d47d062f91471f4e9c5e0d51
• https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_rail.c#L1230-L1238
• https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_rail.c#L1297
• https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_rail.c#L1316-L1327
• https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_rail.c#L386-L394
• https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_rail.c#L395-L399
• https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_rail.c#L401-L404

• CWE-416: Use After Free CWE