CVE-2026-91952: FreeRDP before 3.31.0 Denial of Service via pool_decode_rect

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-835

Description

FreeRDP versions before 3.31.0 contain an infinite-loop denial of service in the pool_decode_rect function when decoding AVC444 metablocks with more region rectangles than preallocated worker array size. A malicious RDP server can send crafted AVC444 graphics updates causing the threaded decode path to loop indefinitely, consuming CPU and preventing normal client operation.

Affected products

FreeRDP: from 3.11.0 (excl.) 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-m85m-3qxv-63h5
https://www.vulncheck.com/advisories/freerdp-before-3.31.0-denial-of-service-via-pool-decode-rect
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-m85m-3qxv-63h5

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