CVE-2026-121952

FreeRDP before 3.32.2 has an out-of-bounds write in the proxy because rdp_read_bitmap_cache_v2_capability_set rejects only numCellCaches values above 5, yet the bitmap cache v2 cell array is later accessed at fixed indices 0 through 4. A client connecting to the proxy can declare fewer than five cell caches in its Confirm Active, causing heap corruption, heap data leakage to the backend, or a crash.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-xc85-4mqc-xgcx
• https://www.vulncheck.com/advisories/freerdp-before-3.32.2-proxy-out-of-bounds-write-via-bitmap-cache-v2-capability
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-xc85-4mqc-xgcx