Buffer overflow in Freerdp
CVE-2026-91964
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.
Vulnerability class: Buffer Overflow
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
Affected products
Weakness classification (CWE)
References
- disclosure@vulncheck.com (vendor-advisory)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-91964?
- CVE-2026-91964 is a high-severity vulnerability in Freerdp, classified under Heap-based Buffer Overflow. CVSS score: 8.8/10. Published 2026-09-15.
- How severe is CVE-2026-91964?
- High severity. CVSS v3 base score is 8.8 out of 10.