Vulnerability in Freerdp
CVE-2026-91951
FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in the urbdrc client channel's urb_send_current_frame_number_result() function. A malicious RDP server can send a crafted 28-byte USB redirection message to trigger a 4-byte write past the allocated 16-byte buffer, causing denial of service when verbose asserts are enabled.
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: 0.004 (32.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 32.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/FreeRDP/FreeRDP/security/advisories/GHSA-h5w2-q35j-443h (Exploit, vendor-advisory, Mitigation, Vendor Advisory)
- www.vulncheck.com/advisories/freerdp-3.14.0-through-3.30.0-out-of-bounds-write-… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-91951?
- CVE-2026-91951 is a medium-severity vulnerability in Freerdp, classified under Reachable Assertion. CVSS score: 6.5/10. Published 2026-09-15.
- How severe is CVE-2026-91951?
- Medium severity. CVSS v3 base score is 6.5 out of 10.