FreeRDP up to 3.30.x AVC444 Metablock Decoder pool_decode_rect infinite loop

Summaryinfo

A vulnerability was found in FreeRDP up to 3.30.x. It has been rated as problematic. Impacted is the function pool_decode_rect of the component AVC444 Metablock Decoder. This manipulation causes infinite loop. The identification of this vulnerability is CVE-2026-91952. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as problematic was found in FreeRDP up to 3.30.x. Affected by this vulnerability is the function pool_decode_rect of the component AVC444 Metablock Decoder. The manipulation with an unknown input leads to a infinite loop vulnerability. The CWE definition for the vulnerability is CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. As an impact it is known to affect availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-91952 since 09/15/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 3.31.0 eliminates this vulnerability.

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Productinfo

Type

• Remote Access Software

Name

• FreeRDP

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.5
• 3.6
• 3.7
• 3.8
• 3.9
• 3.10
• 3.11
• 3.12
• 3.13
• 3.14
• 3.15
• 3.16
• 3.17
• 3.18
• 3.19
• 3.20
• 3.21
• 3.22
• 3.23
• 3.24
• 3.25
• 3.26
• 3.27
• 3.28
• 3.29
• 3.30

License

• open-source

Website

• Product: https://github.com/FreeRDP/FreeRDP/

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