What is CVE-2026-91961?

CVE-2026-91961 is a medium-severity vulnerability in Freerdp, classified under Reachable Assertion. CVSS score: 6.5/10. Published 2026-09-15.

How severe is CVE-2026-91961?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Freerdp

CVE-2026-91961

FreeRDP before 3.31.0 contains a denial-of-service vulnerability in the URBDRC control-transfer request path that fails to validate OutputBufferSize before forwarding to the libusb backend. A malicious RDP server can send a control-transfer request with OutputBufferSize set to 65536, triggering a reachable assertion that terminates the client process.

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.

Affected products

Freerdp

Weakness classification (CWE)

CWE-617 — Reachable Assertion

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-91961?: CVE-2026-91961 is a medium-severity vulnerability in Freerdp, classified under Reachable Assertion. CVSS score: 6.5/10. Published 2026-09-15.
How severe is CVE-2026-91961?: Medium severity. CVSS v3 base score is 6.5 out of 10.