CVE-2026-91953

A flaw was found in FreeRDP. A malicious RDP (Remote Desktop Protocol) server or a man-in-the-middle attacker could exploit a heap buffer overflow vulnerability during connection negotiation, prior to authentication. By sending a specially crafted Server Redirection PDU (Protocol Data Unit) with an oversized LB_LOAD_BALANCE_INFO field, an attacker could cause a denial of service or heap corruption on the client system.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To prevent exploitation of this heap buffer overflow, FreeRDP clients should only be used to connect to trusted RDP servers. This operational control reduces the risk of encountering a malicious server redirection PDU.