CVE-2026-91960: FreeRDP before 3.31.0 Integer Overflow Double Free

Vulnerability summary

CVE-2026-91960 is a high (CVSS 7.1) Integer Overflow or Wraparound vulnerability in freerdp. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 39.8% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 15-09-2026
   PublishedVulnerability first disclosed.
2. 15-09-2026
   Last modifiedVulnerability information updated.

Description

FreeRDP versions before 3.31.0 contain an integer overflow in WinPR's Stream_EnsureRemainingCapacity function that allows remote attackers to cause denial of service. A malicious RD Gateway peer can send a WebSocket Ping frame with a crafted 64-bit extended payload length to trigger integer wraparound, resulting in a double free that crashes the FreeRDP client during connection.

• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.