CVE-2026-91953

Summary

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.

Affected Software

VendorProductVersion RangeStatus
FreeRDPFreeRDP0 < 3.31.0affected
FreeRDPFreeRDP3.31.0unaffected

Weaknesses

  • CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: no
    • Technical Impact: partial

References