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Fencer Intel
high 8.8

CVE-2026-44421 json

FreeRDP RDPGFX CacheToSurface heap-buffer-overflow via clamped-rectangle validation bypass

published 5mo ago modified 3mo ago also EUVD-2026-33433

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits
0
none known

Summary

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client by sending crafted RDPGFX PDUs. The bug is in gdi_CacheToSurface: it validates a destination rectangle that is clamped to UINT16_MAX, but then performs the copy using the original cacheEntry->width/height. This can cause a large out-of-bounds heap write and may lead to client crashes or code execution. This bug is reachable from a malicious RDP server, but only when the client has RDPGFX enabled. This vulnerability is fixed in 3.26.0.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 10 2:3.10.3-12.el10_2.6
  • freerdp3 Debian 14 3.26.0+dfsg-1

debian advisories DEBIAN-CVE-2026-44421

  • freerdp3 Ubuntu 24.04 LTS 3.30.0+dfsg-0ubuntu0.24.04.1
  • freerdp3 Ubuntu 26.04 LTS 3.30.0+dfsg-0ubuntu0.26.04.1

ubuntu advisories UBUNTU-CVE-2026-44421

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_2.6
  • libwinpr RHEL 10.2 2:3.10.3-12.el10_2.6
  • freerdp-libs RHEL 10.2 2:3.10.3-12.el10_2.6
  • freerdp-server RHEL 10.2 2:3.10.3-12.el10_2.6
  • freerdp enterprise linux eus 10.0 2:3.10.3-3.el10_0.9
  • libwinpr enterprise linux eus 10.0 2:3.10.3-3.el10_0.9
  • freerdp-libs enterprise linux eus 10.0 2:3.10.3-3.el10_0.9
  • freerdp-server enterprise linux eus 10.0 2:3.10.3-3.el10_0.9

red hat advisories RHSA-2026:46393RHSA-2026:36203

  • freerdp SLE Workstation Extension 15 SP7, SLE Module for Package Hub 15 SP7 3.10.3-150700.3.17.1
  • freerdp SLES for SAP applications 16.0, SLES 16.0 3.26.0-160000.1.1

suse advisories SUSE-SU-2026:3562-1SUSE-SU-2026:22194-1

  • freerdp openSUSE Leap 16.0 3.26.0-160000.1.1
  • freerdp openSUSE Tumbleweed 3.26.0-3.1

opensuse advisories openSUSE-SU-2026:21116-1openSUSE-SU-2026:10948-1

  • freerdp AlmaLinux 10 2:3.10.3-12.el10_2.6
  • libwinpr AlmaLinux 10 2:3.10.3-12.el10_2.6
  • freerdp-libs AlmaLinux 10 2:3.10.3-12.el10_2.6
  • freerdp-server AlmaLinux 10 2:3.10.3-12.el10_2.6

almalinux advisories ALSA-2026:36203

  • freerdp Rocky Linux 10 2:3.10.3-12.el10_2.6

rocky linux advisories RLSA-2026:36203

Is CVE-2026-44421 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2026-44421 updated cvss 8.8

freerdp: FreeRDP: Arbitrary code execution via crafted RDPGFX PDUs

  • Red Hat Enterprise Linux 6 freerdp, freerdp-libs, freerdp-plugins
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 10) freerdp 3.10.3-12.el10_2.6, libwinpr 3.10.3-12.el10_2.6, freerdp-libs 3.10.3-12.el10_2.6
    fixed: vendor fix RHSA-2026:36203
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) freerdp 3.10.3-3.el10_0.9, libwinpr 3.10.3-3.el10_0.9, freerdp-libs 3.10.3-3.el10_0.9
    fixed: vendor fix RHSA-2026:46393
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) freerdp-server 3.10.3-12.el10_2.6
    fixed: vendor fix RHSA-2026:36203
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) freerdp-server 3.10.3-3.el10_0.9
    fixed: vendor fix RHSA-2026:46393
  • Red Hat Enterprise Linux 7 freerdp, libwinpr, freerdp-libs, freerdp-plugins Red Hat Enterprise Linux 8 freerdp, libwinpr, freerdp-libs Red Hat Enterprise Linux 9 freerdp, libwinpr, freerdp-libs
    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
5mo ago

Exploit prediction

0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff 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 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9

Classification

Weakness

References

Sources

Fencer Intel 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.