CVE-2026-121964: FreeRDP before 3.32.2 Heap Buffer Overflow via rpc_client_recv_fragment

FreeRDP before 3.32.2 contains a heap-based buffer overflow in the RD Gateway RPC client, where rpcclientrecvfragment writes BINDACK and ALTERCONTEXTRESP fragments into a persistent PDU stream after checking only total capacity rather than remaining capacity from the current stream position. A malicious or compromised RD Gateway can send crafted RPC fragments with manipulated allochint and fraglength values to overwrite client heap memory with attacker-controlled data, causing a crash or potentially arbitrary code execution.