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Vulnerability · Published Feb 25, 2026 · Assigned by GitHub_M

CVE-2026-26955FreeRDP has Out-of-bounds Write

High 8.8

In plain English

A high-severity out-of-bounds write in FreeRDP from FreeRDP. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 51% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.8High
Exploit odds (30 days)0.6%top 48.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, a malicious RDP server can trigger a heap buffer overflow in FreeRDP clients using the GDI surface pipeline (e.g., `xfreerdp`) by sending an RDPGFX ClearCodec surface command with an out-of-bounds destination rectangle. The `gdi_SurfaceCommand_ClearCodec()` handler does not call `is_within_surface()` to validate the command rectangle against the destination surface dimensions, allowing attacker-controlled `cmd->left`/`cmd->top` (and subcodec rectangle offsets) to reach image copy routines that write into `surface->data` without bounds enforcement. The OOB write corrupts an adjacent `gdiGfxSurface` struct's `codecs*` pointer with attacker-controlled pixel data, and corruption of `codecs*` is sufficient to reach an indirect function pointer call (`NSC_CONTEXT.decode` at `nsc.c:500`) on a subsequent codec command — full instruction pointer (RIP) control demonstrated in exploitability harness. Users should upgrade to version 3.23.0 to receive a patch.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:10freerdp2:3.10.3-5.el10_1.3ALSA-2026:5939
AlmaLinux:8freerdp2:2.11.7-4.el8_10ALSA-2026:6005
AlmaLinux:9freerdp2:2.11.7-1.el9_7.3ALSA-2026:6004
AlmaLinux:10freerdp-devel2:3.10.3-5.el10_1.3ALSA-2026:5939
AlmaLinux:8freerdp-devel2:2.11.7-4.el8_10ALSA-2026:6005
AlmaLinux:9freerdp-devel2:2.11.7-1.el9_7.3ALSA-2026:6004
AlmaLinux:10freerdp-libs2:3.10.3-5.el10_1.3ALSA-2026:5939
AlmaLinux:8freerdp-libs2:2.11.7-4.el8_10ALSA-2026:6005
AlmaLinux:9freerdp-libs2:2.11.7-1.el9_7.3ALSA-2026:6004
AlmaLinux:10freerdp-server2:3.10.3-5.el10_1.3ALSA-2026:5939
AlmaLinux:10libwinpr2:3.10.3-5.el10_1.3ALSA-2026:5939
AlmaLinux:8libwinpr2:2.11.7-4.el8_10ALSA-2026:6005
AlmaLinux:9libwinpr2:2.11.7-1.el9_7.3ALSA-2026:6004
AlmaLinux:10libwinpr-devel2:3.10.3-5.el10_1.3ALSA-2026:5939
AlmaLinux:8libwinpr-devel2:2.11.7-4.el8_10ALSA-2026:6005
AlmaLinux:9libwinpr-devel2:2.11.7-1.el9_7.3ALSA-2026:6004
Alpine:v3.23freerdp3.23.0-r0ALPINE-CVE-2026-26955
Alpine:v3.24freerdp3.23.0-r0ALPINE-CVE-2026-26955
Debian:12freerdp2no fix listedDEBIAN-CVE-2026-26955
Debian:13freerdp33.15.0+dfsg-2.1+deb13u1DEBIAN-CVE-2026-26955
Debian:14freerdp33.23.0+dfsg-1DEBIAN-CVE-2026-26955
Rocky Linux:8freerdp2:2.11.7-4.el8_10RLSA-2026:6005
Ubuntu:22.04:LTSfreerdp2no fix listedUBUNTU-CVE-2026-26955
Ubuntu:24.04:LTSfreerdp33.5.1+dfsg1-0ubuntu1.4USN-8105-1
Ubuntu:24.04:LTSfreerdp33.5.1+dfsg1-0ubuntu1.4UBUNTU-CVE-2026-26955
Ubuntu:25.10freerdp33.16.0+dfsg-2ubuntu0.3UBUNTU-CVE-2026-26955
Ubuntu:25.10freerdp33.16.0+dfsg-2ubuntu0.3USN-8105-1

Affected products (as reported)

VendorProductVersions
FreeRDP FreeRDP < 3.23.0

Weakness: CWE-787, CWE-805 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References