Double free in FreeRDP - CVE-2026-63652
Published: July 6, 2026 / Updated: August 21, 2026
Vulnerability identifier: #VU136921
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-63652
CWE-ID: CWE-415
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to double free in rdpsnd_server_recv_formats() and rdpsnd_server_context_free() when processing a malformed Client Audio Formats PDU on the rdpsnd server channel. A remote user can send a specially crafted PDU to cause a denial of service.
The issue occurs after successful RDP authentication and requires the server build to include the rdpsnd server channel. The malformed PDU leaves a dangling client_formats pointer that is freed again during session teardown.
Affected software
FreeRDP
How to mitigate CVE-2026-63652
Install security update from vendor's website.
FreeRDP - update to 3.28.0