FreeRDP up to 3.27.x RDP Sound Channel rdpsnd_main.c rdpsnd_server_select_format divide by zero

Summaryinfo

A vulnerability identified as critical has been detected in FreeRDP up to 3.27.x. This affects the function rdpsnd_server_select_format of the file channels/rdpsnd/server/rdpsnd_main.c of the component RDP Sound Channel. The manipulation leads to divide by zero. This vulnerability is traded as CVE-2026-63117. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in FreeRDP up to 3.27.x and classified as critical. This issue affects the function rdpsnd_server_select_format of the file channels/rdpsnd/server/rdpsnd_main.c of the component RDP Sound Channel. The manipulation with an unknown input leads to a divide by zero vulnerability. Using CWE to declare the problem leads to CWE-369. The product divides a value by zero. Impacted is availability. The summary by CVE is:

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, an authenticated RDP client can advertise DVI ADPCM with nBlockAlign equal to 8 and nChannels equal to 2 to make the `bs` calculation in rdpsnd_server_select_format in channels/rdpsnd/server/rdpsnd_main.c equal zero. The subsequent out_frames modulo `bs` operation raises SIGFPE and terminates the server-side rdpsnd channel process. This vulnerability fixed in 3.28.0.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-63117 since 07/15/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 338192 (Linux Distros Unpatched Vulnerability : CVE-2026-63117), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.28.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (338192). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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

License

• open-source

Website

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

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