CVE-2026-91951: FreeRDP 3.14.0 through 3.30.0 Out-of-bounds Write via urbdrc

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-09-15 · updated 2026-09-24
Weakness: CWE-617

Description

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.

Affected products

FreeRDP: from 3.14.0 before 3.31.0 — fixed in 3.31.0

How to fix

Upgrade to a fixed version: FreeRDP 3.31.0. Check the vendor advisory for mitigations.

References

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-h5w2-q35j-443h
https://www.vulncheck.com/advisories/freerdp-3.14.0-through-3.30.0-out-of-bounds-write-via-urbdrc

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