OESA-2026-4656

FreeRDP is a client implementation of the Remote Desktop Protocol (RDP) that follows Microsoft's open specifications. This package provides the client applications xfreerdp.

Security Fix(es):

FreeRDP versions before 3.31.0 contain a heap buffer overflow vulnerability in nego_send_negotiation_request() that fails to validate the LB_LOAD_BALANCE_INFO field length before writing to a fixed 512-byte buffer. A malicious RDP server or man-in-the-middle can send a Server Redirection PDU with an oversized LB_LOAD_BALANCE_INFO value to overflow the buffer with attacker-controlled content, causing denial of service or heap corruption before authentication completes.(CVE-2026-91953)

FreeRDP before 3.31.0 contains an out-of-bounds read vulnerability in the URBDRC channel's func_get_ep_desc function that indexes interface arrays by position instead of protocol field InterfaceNumber. A malicious RDP server can send a crafted SELECT_CONFIGURATION message with permuted InterfaceNumber values to read past allocated heap memory and crash the client.(CVE-2026-91956)

FreeRDP is an implementation of the Remote Desktop Protocol (RDP) open sourced by the FreeRDP team. FreeRDP versions before 3.31.0 have a buffer error vulnerability. This vulnerability originates from buffer over-reading in the rts_read_result function in the RPC gateway transport parser. An attacker can trigger an out-of-bounds read by sending a specially crafted BIND_ACK PDU with truncated result entries, causing the process to terminate.(CVE-2026-91959)

FreeRDP versions before 3.31.0 contain an uninitialized heap memory disclosure vulnerability in the urbdrc USB redirection channel. A malicious RDP server can induce failing USB transfers to read uninitialized heap memory from the client, defeating ASLR and enabling remote code execution when chained with memory corruption vulnerabilities.(CVE-2026-91963)

FreeRDP versions before 3.31.0 contain a heap-based buffer overflow in nego_send_negotiation_request when processing Server Redirection PDU messages with attacker-controlled LoadBalanceInfo fields. A malicious RDP server can trigger the overflow by sending an arbitrary-length field that gets written to a fixed 512-byte buffer without validation, causing client crashes or potential code execution when chained with memory disclosure.(CVE-2026-91964)