FreeRDP up to 3.32.1 RDG Control Packet Processing rdg_process_control_packet infinite loop

Summaryinfo

A vulnerability marked as problematic has been reported in FreeRDP. The affected element is the function rdg_process_control_packet of the component RDG Control Packet Processing. This manipulation causes infinite loop. This vulnerability is registered as CVE-2026-121400. Remote exploitation of the attack is possible. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in FreeRDP. It has been declared as problematic. Affected by this vulnerability is the function rdg_process_control_packet of the component RDG Control Packet Processing. 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 before 3.32.2 contains a denial-of-service vulnerability in rdg_process_control_packet that allows a malicious RD Gateway to exhaust client CPU by sending an incomplete keepalive control packet. Attackers completing the RDG tunnel-open exchange then send an eight-byte header with packetLength 0xFFFF and withhold the body, causing an unbounded no-progress read loop that spins one client thread at full CPU.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-121400 since 11/03/2026. The exploitation appears to be easy. The attack can be launched remotely. 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 3.32.2 eliminates this vulnerability.

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Productinfo

Type

• Remote Access Software

Name

• FreeRDP

Version

• 1.0.0
• 1.0.1
• 1.0.2
• 1.1.0-beta+2013071101
• 1.1.0-beta1
• 2.0.0
• 2.0.0-beta1
• 2.0.0-beta1+android11
• 2.0.0-rc4
• 2.1.0
• 2.1.1
• 2.1.2
• 2.2.0
• 2.3.0
• 2.4.0
• 2.4.1
• 2.7.0
• 2.8.1
• 2.9.0
• 2.11.0
• 2.11.5
• 2.11.6
• 2.11.8
• 3.0.0
• 3.0.0-beta2
• 3.0.0-beta3
• 3.1
• 3.2.0
• 3.4
• 3.5.0
• 3.5.1
• 3.9.0
• 3.20.0
• 3.20.1
• 3.21.0
• 3.22
• 3.22.0
• 3.23.0
• 3.24.0
• 3.24.2
• 3.25.0
• 3.26.0
• 3.27
• 3.27.0
• 3.27.1
• 3.28.0
• 3.29.0
• 3.30.0
• 3.31
• 3.31.0
• 3.32.0
• 3.32.1

License

• open-source

Website

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

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