Heap-based buffer overflow in FreeRDP - CVE-2026-33986
Published: April 8, 2026
Vulnerability identifier: #VU125367
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-33986
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: FreeRDP
Affected software:
FreeRDP
FreeRDP
Detailed vulnerability description
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to a heap-based buffer overflow in yuv_ensure_buffer() in libfreerdp/codec/h264.c when processing crafted RDPGFX AVC420 frames from a malicious RDP server. A remote attacker can send crafted H.264 NAL units to execute arbitrary code.
User interaction is required to connect to a malicious RDP server.
How to mitigate CVE-2026-33986
Install security update from vendor's website.