CVE-2026-121957

FreeRDP before 3.32.2 contains a heap-based buffer overflow in the RD Gateway RPC client, where rpc_client_recv_fragment writes BIND_ACK and ALTER_CONTEXT_RESP 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 alloc_hint and frag_length values to overwrite client heap memory with attacker-controlled data, causing a crash or potentially arbitrary code execution.

FreeRDP before 3.32.2 contains a use-after-free vulnerability in the asynchronous dynamic rdpsnd channel that allows malicious RDP servers to trigger freed callback access by closing the channel with queued audio PDUs. Attackers can send a training PDU then close the channel so the playback thread reads the freed callback in rdpsnd_virtual_channel_write, crashing the client.

FreeRDP before 3.32.2 contains a heap buffer overflow in transport_default_read_pdu when handling partial Early User Authorization reads during PROTOCOL_HYBRID_EX CredSSP. A malicious RDP server can split the four-byte EUA result into short reads that advance the stream pointer beyond the 16 KiB allocation, causing an out-of-bounds write and client denial of service.

FreeRDP before 3.32.2 contains a use-after-free vulnerability in the freerdp-proxy DRDYNVC tracker when intercepting the drdynvc channel. A malicious target server can repeatedly send CREATE_REQUEST_PDU for an active channel id, racing front DATA handling to free a borrowed context and crash the proxy process.

FreeRDP before 3.32.2 contains a denial of service vulnerability in the NLA-enabled shadow server when a CredSSP TSRequest omits negoTokens. Unauthenticated attackers can send a crafted seven-byte TSRequest containing only the version field to trigger a fatal WINPR_ASSERT and abort the server process.

FreeRDP before 3.32.2 contains an infinite loop vulnerability in websocket_context_read that fails to handle a zero BIO result with payload outstanding. A malicious RD Gateway can send a truncated WebSocket frame followed by a TLS close_notify, causing a client thread to spin and consume CPU until killed.

FreeRDP through 3.32.1 has a heap out-of-bounds write in the RDPGFX client because the delete_surface callback truncates surface hash keys to 16 bits, leaving the surface table inconsistent so HashTable_GetKeys writes past its allocated key array. A malicious or man-in-the-middle RDP server can exploit this by creating surfaceId 0xFFFF, closing the RDPGFX channel, sending repeated DELETESURFACE PDUs, and then sending ENDFRAME or RESETGRAPHICS.

FreeRDP before 3.32.2 contains a double free in the WinPR Kerberos SSPI retrieveSomeTgt function, which installs the krb5 default realm into a target principal that has an empty realm without taking ownership of it. Unauthenticated remote clients can send a crafted NLA/CredSSP u2u TGT request whose server-name component contains '@' to corrupt the heap and crash the server process.

FreeRDP before 3.32.2 contains a use-after-free vulnerability in Emulate_SCardReleaseContext that frees the emulated SCardContext before its worker thread is cancelled and joined. A malicious server can send ESTABLISHCONTEXT, a long-timeout GETSTATUSCHANGE, then RELEASECONTEXT smartcard IRPs to corrupt heap memory or crash clients using smartcard emulation.

FreeRDP before 3.32.2 has a heap out-of-bounds write in the planar codec because freerdp_bitmap_planar_context_reset commits new dimensions before buffer reallocation succeeds, and a failed ResetGraphics is only logged. A malicious RDP server can send an oversized ResetGraphics PDU, then a GFX PLANAR command, to corrupt client heap memory and crash the client.