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Vulnerability · Published Feb 25, 2026 · Assigned by GitHub_M

CVE-2026-26965FreeRDP 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 0.7% (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 47.1% 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, in the RLE planar decode path, `planar_decompress_plane_rle()` writes into `pDstData` at `((nYDst+y) * nDstStep) + (4*nXDst) + nChannel` without verifying that `(nYDst+nSrcHeight)` fits in the destination height or that `(nXDst+nSrcWidth)` fits in the destination stride. When `TempFormat != DstFormat`, `pDstData` becomes `planar->pTempData` (sized for the desktop), while `nYDst` is only validated against the **surface** by `is_within_surface()`. A malicious RDP server can exploit this to perform a heap out-of-bounds write with attacker-controlled offset and pixel data on any connecting FreeRDP client. The OOB write reaches up to 132,096 bytes past the temp buffer end, and on the brk heap (desktop ≤ 128×128), an adjacent `NSC_CONTEXT` struct's `decode` function pointer is overwritten with attacker-controlled pixel data — control-flow–relevant corruption (function pointer overwritten) demonstrated under deterministic heap layout (`nsc->decode = 0xFF414141FF414141`). Version 3.23.0 fixes the vulnerability.

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-2026-26965
Alpine:v3.24freerdp3.23.0-r0ALPINE-CVE-2026-26965
Debian:12freerdp2no fix listedDEBIAN-CVE-2026-26965
Debian:13freerdp33.15.0+dfsg-2.1+deb13u1DEBIAN-CVE-2026-26965
Debian:14freerdp33.23.0+dfsg-1DEBIAN-CVE-2026-26965
Rocky Linux:8freerdp2:2.11.7-4.el8_10RLSA-2026:6005
Ubuntu:22.04:LTSfreerdp2no fix listedUBUNTU-CVE-2026-26965
Ubuntu:24.04:LTSfreerdp33.5.1+dfsg1-0ubuntu1.4USN-8105-1
Ubuntu:24.04:LTSfreerdp33.5.1+dfsg1-0ubuntu1.4UBUNTU-CVE-2026-26965
Ubuntu:25.10freerdp33.16.0+dfsg-2ubuntu0.3UBUNTU-CVE-2026-26965
Ubuntu:25.10freerdp33.16.0+dfsg-2ubuntu0.3USN-8105-1

Affected products (as reported)

VendorProductVersions
FreeRDP FreeRDP < 3.23.0

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

References