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Medium severity · published Aug 19, 2026
CVE-2026-63117
FreeRDP: Denial of service through ADPCM frame size calculation
6.5
CVSS
0.6%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 46% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FR
FreeRDP · FreeRDP
< 3.28.0 · source: vendor, NVD
Affected product
FR
FreeRDP
FreeRDP
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-63117
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-63117
Patch
https://github.com/FreeRDP/FreeRDP/commit/b78fc0b138fe8f08a8b102e193ffb32986f4449a
Issue Tracking
https://github.com/FreeRDP/FreeRDP/pull/12980
Release Notes
https://github.com/FreeRDP/FreeRDP/releases/tag/3.28.0
Vendor Advisory
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-v64m-xxfw-hrv6
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