Integer overflow in Freerdp
CVE-2026-91960
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.
Vulnerability class: Integer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (39.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 39.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: -0.000
Affected products
Weakness classification (CWE)
References
- github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vccg-35r5-8jrf (Exploit, vendor-advisory, Mitigation, Vendor Advisory)
- www.vulncheck.com/advisories/freerdp-before-3.31.0-integer-overflow-double-free (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-91960?
- CVE-2026-91960 is a medium-severity vulnerability in Freerdp, classified under Integer Overflow or Wraparound. CVSS score: 6.5/10. Published 2026-09-15.
- How severe is CVE-2026-91960?
- Medium severity. CVSS v3 base score is 6.5 out of 10.