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Vulnerability · Published Mar 13, 2026 · Assigned by GitHub_M

CVE-2026-31806FreeRDP has a Heap Buffer Overflow in nsc_process_message() via Unchecked SURFACE_BITS_COMMAND Bitmap Dimensions

High 8.8

In plain English

A high-severity heap buffer overflow in FreeRDP from FreeRDP. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 53% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.8High
Exploit odds (30 days)0.7%top 47.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, the gdi_surface_bits() function processes SURFACE_BITS_COMMAND messages sent by the RDP server. When the command is handled using NSCodec, the bmp.width and bmp.height values provided by the server are not properly validated against the actual desktop dimensions. A malicious RDP server can supply crafted bmp.width and bmp.height values that exceed the expected surface size. Because these values are used during bitmap decoding and memory operations without proper bounds checking, this can lead to a heap buffer overflow. Since the attacker can also control the associated pixel data transmitted by the server, the overflow may be exploitable to overwrite adjacent heap memory. This vulnerability is fixed in 3.24.0.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:10freerdp2:3.10.3-5.el10_1.5ALSA-2026:6799
AlmaLinux:8freerdp2:2.11.7-6.el8_10ALSA-2026:6918
AlmaLinux:9freerdp2:2.11.7-1.el9_7.5ALSA-2026:6340
AlmaLinux:10freerdp-devel2:3.10.3-5.el10_1.5ALSA-2026:6799
AlmaLinux:8freerdp-devel2:2.11.7-6.el8_10ALSA-2026:6918
AlmaLinux:9freerdp-devel2:2.11.7-1.el9_7.5ALSA-2026:6340
AlmaLinux:10freerdp-libs2:3.10.3-5.el10_1.5ALSA-2026:6799
AlmaLinux:8freerdp-libs2:2.11.7-6.el8_10ALSA-2026:6918
AlmaLinux:9freerdp-libs2:2.11.7-1.el9_7.5ALSA-2026:6340
AlmaLinux:10freerdp-server2:3.10.3-5.el10_1.5ALSA-2026:6799
AlmaLinux:10libwinpr2:3.10.3-5.el10_1.5ALSA-2026:6799
AlmaLinux:8libwinpr2:2.11.7-6.el8_10ALSA-2026:6918
AlmaLinux:9libwinpr2:2.11.7-1.el9_7.5ALSA-2026:6340
AlmaLinux:10libwinpr-devel2:3.10.3-5.el10_1.5ALSA-2026:6799
AlmaLinux:8libwinpr-devel2:2.11.7-6.el8_10ALSA-2026:6918
AlmaLinux:9libwinpr-devel2:2.11.7-1.el9_7.5ALSA-2026:6340
Alpine:v3.23freerdp3.24.0-r0ALPINE-CVE-2026-31806
Alpine:v3.24freerdp3.24.0-r0ALPINE-CVE-2026-31806
Debian:12freerdp2no fix listedDEBIAN-CVE-2026-31806
Debian:13freerdp33.15.0+dfsg-2.1+deb13u2DEBIAN-CVE-2026-31806
Debian:14freerdp33.24.0+dfsg-1DEBIAN-CVE-2026-31806
Rocky Linux:10freerdp2:3.10.3-5.el10_1.5RLSA-2026:6799
Rocky Linux:8freerdp2:2.11.7-6.el8_10RLSA-2026:6918
Rocky Linux:9freerdp2:2.11.7-1.el9_7.5RLSA-2026:6340
Ubuntu:22.04:LTSfreerdp2no fix listedUBUNTU-CVE-2026-31806
Ubuntu:24.04:LTSfreerdp33.30.0+dfsg-0ubuntu0.24.04.1USN-8561-1
Ubuntu:24.04:LTSfreerdp33.30.0+dfsg-0ubuntu0.24.04.1UBUNTU-CVE-2026-31806
Ubuntu:25.10freerdp3no fix listedUBUNTU-CVE-2026-31806
Ubuntu:26.04:LTSfreerdp33.30.0+dfsg-0ubuntu0.26.04.1USN-8561-1

Affected products (as reported)

VendorProductVersions
FreeRDP FreeRDP < 3.24.0

Weakness: CWE-122, CWE-131 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References