What’s Vulnerable › Vulnerabilities

CVE-2026-63117: FreeRDP: Denial of service through ADPCM frame size calculation

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-19 · updated 2026-10-26
• Weakness: CWE-369

Description

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.

Affected products

• FreeRDP: before 3.28.0 — fixed in 3.28.0

How to fix

Upgrade to a fixed version: FreeRDP 3.28.0. Check the vendor advisory for mitigations.

References

• https://github.com/FreeRDP/FreeRDP/commit/b78fc0b138fe8f08a8b102e193ffb32986f4449a
• https://github.com/FreeRDP/FreeRDP/pull/12980
• https://github.com/FreeRDP/FreeRDP/releases/tag/3.28.0
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-v64m-xxfw-hrv6

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