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Fencer Vulns
high 8.8

CVE-2026-26955 json

FreeRDP has Out-of-bounds Write

published 2026-02-25 8 mo ago modified 2026-07-15 3 mo ago also EUVD-2026-8739

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 51%
public exploits
0
none known

Summary

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.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 10 2:3.10.3-5.el10_1.3, 2:3.10.3-12.el10_2.2
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support 2:3.10.3-3.el10_0.3
  • Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support 0:2.1.1-5.el7_9.5
  • Red Hat Red Hat Enterprise Linux 8 2:2.11.7-4.el8_10
  • Red Hat Red Hat Enterprise Linux 8.2 Advanced Update Support 2:2.0.0-46.rc4.el8_2.8
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 2:2.2.0-10.el8_4
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 2:2.2.0-10.el8_4
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 2:2.2.0-7.el8_6.3
  • Red Hat Red Hat Enterprise Linux 8.6 Telecommunications Update Service 2:2.2.0-7.el8_6.3
  • Red Hat Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions 2:2.2.0-7.el8_6.3
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service 2:2.2.0-12.el8_8.3
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 2:2.2.0-12.el8_8.3
  • Red Hat Red Hat Enterprise Linux 9 2:2.11.7-1.el9_7.3
  • Red Hat Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions 2:2.4.1-3.el9_0.2
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 2:2.4.1-6.el9_2.4
  • Red Hat Red Hat Enterprise Linux 9.4 Extended Update Support 2:2.11.2-1.el9_4.3
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support 2:2.11.7-1.el9_6.5
  • freerdp3 Debian 13 3.15.0+dfsg-2.1+deb13u1
  • freerdp3 Debian 14 3.23.0+dfsg-1

debian advisories DEBIAN-CVE-2026-26955

  • freerdp3 Ubuntu 24.04 LTS 3.5.1+dfsg1-0ubuntu1.4
  • freerdp3 Ubuntu 25.10 3.16.0+dfsg-2ubuntu0.3

ubuntu advisories UBUNTU-CVE-2026-26955

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • freerdp RHEL 10.2 2:3.10.3-12.el10_2.2
  • libwinpr RHEL 10.2 2:3.10.3-12.el10_2.2
  • freerdp-libs RHEL 10.2 2:3.10.3-12.el10_2.2
  • freerdp-server RHEL 10.2 2:3.10.3-12.el10_2.2
  • freerdp RHEL 9 2:2.11.7-1.el9_7.3
  • libwinpr RHEL 9 2:2.11.7-1.el9_7.3
  • freerdp-libs RHEL 9 2:2.11.7-1.el9_7.3
  • freerdp RHEL 8 2:2.11.7-4.el8_10

red hat advisories RHSA-2026:19033RHSA-2026:7292RHSA-2026:6764RHSA-2026:6712RHSA-2026:6665RHSA-2026:6616

  • freerdp SLE Workstation Extension 15 SP7, SLE Module for Package Hub 15 SP7 3.10.3-150700.3.9.1
  • freerdp2 SLE Workstation Extension 15 SP7, SLE Module for Package Hub 15 SP7 2.11.7-150700.3.14.1
  • freerdp SLE Module for Package Hub 15 SP7, openSUSE Leap 15.6 2.11.2-150600.4.18.1
  • freerdp SLE Module for Package Hub 15 SP7 2.4.0-150400.3.47.1
  • freerdp SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 2.1.2-12.63.1

suse advisories SUSE-SU-2026:1398-1SUSE-SU-2026:1165-1SUSE-SU-2026:1164-1SUSE-SU-2026:1160-1SUSE-SU-2026:1129-1

  • freerdp2 openSUSE Tumbleweed 2.11.7-6.1
  • freerdp openSUSE Tumbleweed 3.24.1-1.1

opensuse advisories openSUSE-SU-2026:10459-1openSUSE-SU-2026:10408-1

  • freerdp AlmaLinux 9 2:2.11.7-1.el9_7.3
  • libwinpr AlmaLinux 9 2:2.11.7-1.el9_7.3
  • freerdp-libs AlmaLinux 9 2:2.11.7-1.el9_7.3
  • freerdp AlmaLinux 8 2:2.11.7-4.el8_10
  • libwinpr AlmaLinux 8 2:2.11.7-4.el8_10
  • freerdp-libs AlmaLinux 8 2:2.11.7-4.el8_10
  • freerdp AlmaLinux 10 2:3.10.3-5.el10_1.3
  • libwinpr AlmaLinux 10 2:3.10.3-5.el10_1.3

almalinux advisories ALSA-2026:6004ALSA-2026:6005ALSA-2026:5939

  • freerdp Rocky Linux 8 2:2.11.7-4.el8_10

rocky linux advisories RLSA-2026:6005

  • freerdp Alpine 3.24, Alpine 3.23 3.23.0-r0

alpine advisories ALPINE-CVE-2026-26955

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-26955 updated cvss 8.8

freerdp: FreeRDP: Arbitrary code execution via heap buffer overflow in GDI surface pipeline

  • Red Hat CodeReady Linux Builder EUS (v.9.4) freerdp-devel 2.11.2-1.el9_4.3, libwinpr-devel 2.11.2-1.el9_4.3, freerdp-debuginfo 2.11.2-1.el9_4.3, libwinpr-debuginfo 2.11.2-1.el9_4.3, freerdp-debugsource 2.11.2-1.el9_4.3, freerdp-libs-debuginfo 2.11.2-1.el9_4.3
    fixed: vendor fix RHSA-2026:6384
  • Red Hat CodeReady Linux Builder EUS (v.9.6) freerdp-devel 2.11.7-1.el9_6.5, libwinpr-devel 2.11.7-1.el9_6.5, freerdp-debuginfo 2.11.7-1.el9_6.5, libwinpr-debuginfo 2.11.7-1.el9_6.5, freerdp-debugsource 2.11.7-1.el9_6.5, freerdp-libs-debuginfo 2.11.7-1.el9_6.5
    fixed: vendor fix RHSA-2026:6385
  • Red Hat Enterprise Linux AppStream (v. 8) freerdp 2.11.7-4.el8_10, libwinpr 2.11.7-4.el8_10, freerdp-libs 2.11.7-4.el8_10
    fixed: vendor fix RHSA-2026:6005
  • Red Hat Enterprise Linux AppStream (v. 9) freerdp 2.11.7-1.el9_7.3, libwinpr 2.11.7-1.el9_7.3, freerdp-libs 2.11.7-1.el9_7.3
    fixed: vendor fix RHSA-2026:6004
  • Red Hat Enterprise Linux AppStream (v. 10) freerdp 3.10.3-5.el10_1.3, freerdp 3.10.3-12.el10_2.2, libwinpr 3.10.3-5.el10_1.3, libwinpr 3.10.3-12.el10_2.2, freerdp-libs 3.10.3-5.el10_1.3, freerdp-libs 3.10.3-12.el10_2.2
    fixed: vendor fix RHSA-2026:5939
  • Red Hat Enterprise Linux AppStream AUS (v. 8.2) freerdp 2.0.0-46.rc4.el8_2.8, libwinpr 2.0.0-46.rc4.el8_2.8, freerdp-libs 2.0.0-46.rc4.el8_2.8
    fixed: vendor fix RHSA-2026:6712
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) freerdp 2.2.0-10.el8_4, libwinpr 2.2.0-10.el8_4, freerdp-libs 2.2.0-10.el8_4
    fixed: vendor fix RHSA-2026:6616
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) freerdp 2.2.0-7.el8_6.3, libwinpr 2.2.0-7.el8_6.3, freerdp-libs 2.2.0-7.el8_6.3 Red Hat Enterprise Linux AppStream E4S (v.8.6) freerdp 2.2.0-7.el8_6.3, libwinpr 2.2.0-7.el8_6.3, freerdp-libs 2.2.0-7.el8_6.3
    fixed: vendor fix RHSA-2026:6665
show 15 more
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) freerdp 2.2.0-12.el8_8.3, libwinpr 2.2.0-12.el8_8.3, freerdp-libs 2.2.0-12.el8_8.3
    fixed: vendor fix RHSA-2026:6764
  • Red Hat Enterprise Linux AppStream E4S (v.9.0) freerdp 2.4.1-3.el9_0.2, libwinpr 2.4.1-3.el9_0.2, freerdp-libs 2.4.1-3.el9_0.2
    fixed: vendor fix RHSA-2026:6395
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) freerdp 2.4.1-6.el9_2.4, libwinpr 2.4.1-6.el9_2.4, freerdp-libs 2.4.1-6.el9_2.4
    fixed: vendor fix RHSA-2026:6396
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) freerdp 3.10.3-3.el10_0.3, libwinpr 3.10.3-3.el10_0.3, freerdp-libs 3.10.3-3.el10_0.3
    fixed: vendor fix RHSA-2026:5936
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) freerdp 2.11.2-1.el9_4.3, libwinpr 2.11.2-1.el9_4.3, freerdp-libs 2.11.2-1.el9_4.3
    fixed: vendor fix RHSA-2026:6384
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) freerdp 2.11.7-1.el9_6.5, libwinpr 2.11.7-1.el9_6.5, freerdp-libs 2.11.7-1.el9_6.5
    fixed: vendor fix RHSA-2026:6385
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) freerdp 2.2.0-10.el8_4, libwinpr 2.2.0-10.el8_4, freerdp-libs 2.2.0-10.el8_4
    fixed: vendor fix RHSA-2026:6616
  • Red Hat Enterprise Linux AppStream TUS (v.8.6) freerdp 2.2.0-7.el8_6.3, libwinpr 2.2.0-7.el8_6.3, freerdp-libs 2.2.0-7.el8_6.3
    fixed: vendor fix RHSA-2026:6665
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) freerdp 2.2.0-12.el8_8.3, libwinpr 2.2.0-12.el8_8.3, freerdp-libs 2.2.0-12.el8_8.3
    fixed: vendor fix RHSA-2026:6764
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) freerdp-devel 2.11.7-1.el9_7.3, libwinpr-devel 2.11.7-1.el9_7.3, freerdp-debuginfo 2.11.7-1.el9_7.3, libwinpr-debuginfo 2.11.7-1.el9_7.3, freerdp-debugsource 2.11.7-1.el9_7.3, freerdp-libs-debuginfo 2.11.7-1.el9_7.3
    fixed: vendor fix RHSA-2026:6004
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) freerdp-server 3.10.3-5.el10_1.3, freerdp-server 3.10.3-12.el10_2.2
    fixed: vendor fix RHSA-2026:5939
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) freerdp-server 3.10.3-3.el10_0.3
    fixed: vendor fix RHSA-2026:5936
  • Red Hat Enterprise Linux CRB (v. 8) freerdp-devel 2.11.7-4.el8_10, freerdp-debuginfo 2.11.7-4.el8_10, libwinpr-debuginfo 2.11.7-4.el8_10, freerdp-debugsource 2.11.7-4.el8_10, freerdp-libs-debuginfo 2.11.7-4.el8_10
    fixed: vendor fix RHSA-2026:6005
  • Red Hat Enterprise Linux Server (v. 7 ELS) freerdp 2.1.1-5.el7_9.5, libwinpr 2.1.1-5.el7_9.5, freerdp-libs 2.1.1-5.el7_9.5 Red Hat Enterprise Linux Server Optional (v. 7 ELS) freerdp-devel 2.1.1-5.el7_9.5, libwinpr-devel 2.1.1-5.el7_9.5, freerdp-debuginfo 2.1.1-5.el7_9.5
    fixed: vendor fix RHSA-2026:7292
  • Red Hat Enterprise Linux 6 freerdp, freerdp-libs, freerdp-plugins
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
8 mo ago

Exploit prediction

0.65% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-mr6w-ch7c-mqqj referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CISA ADP 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

  • FreeRDP FreeRDP
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 8.2 Advanced Update Support
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  • Red Hat Red Hat Enterprise Linux 8.6 Telecommunications Update Service
  • Red Hat Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.4 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 6

Classification

Weakness
  • CWE-787 Out-of-bounds Write
  • CWE-805 Buffer Access with Incorrect Length Value

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.