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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.006 (46.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/FreeRDP/FreeRDP/security/advisories/GHSA-2vf2-grvj-6g8x (vendor-advisory)
- www.vulncheck.com/advisories/freerdp-2.0.0-through-3.30.0-heap-buffer-overflow-… (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.