Skip to content
Fencer Vulns
high 7.5

CVE-2026-33986 json

FreeRDP: H.264 YUV Buffer Dimension Desync - Heap OOB Write

published 2026-03-30 7 mo ago modified 2026-07-15 3 mo ago also EUVD-2026-17233

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 19%
public exploits
0
none known

Summary

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, in yuv_ensure_buffer() in libfreerdp/codec/h264.c, h264->width and h264->height are updated before the reallocation loop. If any winpr_aligned_recalloc() call fails, the function returns FALSE but width/height are already inflated. This issue has been patched in version 3.24.2.

Patch / fix

  • freerdp freerdp 3.24.2
  • freerdp3 Debian 13 3.15.0+dfsg-2.1+deb13u2
  • freerdp3 Debian 14 3.24.2+dfsg-1

debian advisories DEBIAN-CVE-2026-33986

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

ubuntu advisories UBUNTU-CVE-2026-33986

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 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 3.24.2-1.1

opensuse advisories openSUSE-SU-2026:21116-1openSUSE-SU-2026:10633-1

  • freerdp Alpine 3.24, Alpine 3.23 3.24.2-r0

alpine advisories ALPINE-CVE-2026-33986

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-2026-33986 updated cvss 7.5

FreeRDP: FreeRDP: Arbitrary code execution or denial of service via H.264 codec memory allocation vulnerability

  • Red Hat Enterprise Linux 6 freerdp, freerdp-libs, freerdp-plugins Red Hat Enterprise Linux 7 freerdp, libwinpr, freerdp-libs, freerdp-plugins
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 freerdp, libwinpr, freerdp-libs Red Hat Enterprise Linux 9 freerdp, libwinpr, freerdp-libs Red Hat Enterprise Linux 10 freerdp
    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
none
Automatable
no
Technical impact
total
Assessed
7 mo ago

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:H/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
  • CWE-122 Heap-based Buffer Overflow
  • CWE-131 Incorrect Calculation of Buffer Size

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.