Heap-based buffer overflow in FreeRDP - CVE-2026-31806
Published: April 8, 2026
Vulnerability identifier: #VU125361
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-31806
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 nsc_process_message() when processing SURFACE_BITS_COMMAND messages using NSCodec. A remote attacker can send a specially crafted RDP server message with oversized bitmap dimensions to execute arbitrary code.
The issue can be triggered when a FreeRDP client connects to a malicious RDP server.
How to mitigate CVE-2026-31806
Install security update from vendor's website.