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Fencer Vulns
high 7.5

CVE-2026-33984 json

FreeRDP: ClearCodec resize_vbar_entry() Heap OOB Write

published 2026-03-30 7 mo ago modified 2026-07-15 3 mo ago also EUVD-2026-17229

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

Summary

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, in resize_vbar_entry() in libfreerdp/codec/clear.c, vBarEntry->size is updated to vBarEntry->count before the winpr_aligned_recalloc() call. If realloc fails, size is inflated while pixels still points to the old, smaller buffer. On a subsequent call where count <= size (the inflated value), realloc is skipped. The caller then writes count * bpp bytes of attacker-controlled pixel data into the undersized buffer, causing a heap buffer overflow. This issue has been patched in version 3.24.2.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 10 2:3.10.3-5.el10_1.6, 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_0.6
  • Red Hat Red Hat Enterprise Linux 8 2:2.11.7-7.el8_10
  • Red Hat Red Hat Enterprise Linux 8.2 Advanced Update Support 2:2.0.0-46.rc4.el8_2.11
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 2:2.2.0-13.el8_4
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 2:2.2.0-13.el8_4
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 2:2.2.0-7.el8_6.6
  • Red Hat Red Hat Enterprise Linux 8.6 Telecommunications Update Service 2:2.2.0-7.el8_6.6
  • Red Hat Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions 2:2.2.0-7.el8_6.6
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service 2:2.2.0-12.el8_8.6
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 2:2.2.0-12.el8_8.6
  • Red Hat Red Hat Enterprise Linux 9 2:2.11.7-1.el9_7.6, 2:2.11.7-7.el9_8.1
  • Red Hat Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions 2:2.4.1-3.el9_0.5
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 2:2.4.1-6.el9_2.7
  • Red Hat Red Hat Enterprise Linux 9.4 Extended Update Support 2:2.11.2-1.el9_4.6
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support 2:2.11.7-1.el9_6.8
  • freerdp3 Debian 13 3.15.0+dfsg-2.1+deb13u2
  • freerdp3 Debian 14 3.24.2+dfsg-1

debian advisories DEBIAN-CVE-2026-33984

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

ubuntu advisories UBUNTU-CVE-2026-33984

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 9 2:2.11.7-7.el9_8.1
  • libwinpr RHEL 9 2:2.11.7-7.el9_8.1
  • freerdp-libs RHEL 9 2:2.11.7-7.el9_8.1
  • 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 8 2:2.11.7-7.el8_10

red hat advisories RHSA-2026:19349RHSA-2026:19033RHSA-2026:12359RHSA-2026:12388RHSA-2026:11651RHSA-2026:11649

  • freerdp SLE Workstation Extension 15 SP7, SLE Module for Package Hub 15 SP7 3.10.3-150700.3.17.1

suse advisories SUSE-SU-2026:3562-1

  • freerdp openSUSE Tumbleweed 3.24.2-1.1

opensuse advisories openSUSE-SU-2026:10633-1

  • freerdp AlmaLinux 8 2:2.11.7-7.el8_10
  • libwinpr AlmaLinux 8 2:2.11.7-7.el8_10
  • freerdp-libs AlmaLinux 8 2:2.11.7-7.el8_10
  • freerdp AlmaLinux 9 2:2.11.7-1.el9_7.6
  • libwinpr AlmaLinux 9 2:2.11.7-1.el9_7.6
  • freerdp-libs AlmaLinux 9 2:2.11.7-1.el9_7.6
  • freerdp AlmaLinux 10 2:3.10.3-5.el10_1.6
  • libwinpr AlmaLinux 10 2:3.10.3-5.el10_1.6

almalinux advisories ALSA-2026:8945ALSA-2026:8457ALSA-2026:8458

  • freerdp Rocky Linux 8 2:2.11.7-7.el8_10
  • freerdp Rocky Linux 9 2:2.11.7-1.el9_7.6
  • freerdp Rocky Linux 10 2:3.10.3-5.el10_1.6

rocky linux advisories RLSA-2026:8945RLSA-2026:8457RLSA-2026:8458

  • freerdp Alpine 3.24, Alpine 3.23 3.24.2-r0

alpine advisories ALPINE-CVE-2026-33984

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-2026-33984 updated cvss 7.5

FreeRDP: FreeRDP: Heap buffer overflow allows arbitrary code execution via crafted pixel data

  • 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 CodeReady Linux Builder EUS (v.9.4) freerdp-devel 2.11.2-1.el9_4.6, libwinpr-devel 2.11.2-1.el9_4.6, freerdp-debuginfo 2.11.2-1.el9_4.6, libwinpr-debuginfo 2.11.2-1.el9_4.6, freerdp-debugsource 2.11.2-1.el9_4.6, freerdp-libs-debuginfo 2.11.2-1.el9_4.6
    fixed: vendor fix RHSA-2026:10709
  • Red Hat CodeReady Linux Builder EUS (v.9.6) freerdp-devel 2.11.7-1.el9_6.8, libwinpr-devel 2.11.7-1.el9_6.8, freerdp-debuginfo 2.11.7-1.el9_6.8, libwinpr-debuginfo 2.11.7-1.el9_6.8, freerdp-debugsource 2.11.7-1.el9_6.8, freerdp-libs-debuginfo 2.11.7-1.el9_6.8
    fixed: vendor fix RHSA-2026:9656
  • Red Hat Enterprise Linux AppStream (v. 8) freerdp 2.11.7-7.el8_10, libwinpr 2.11.7-7.el8_10, freerdp-libs 2.11.7-7.el8_10
    fixed: vendor fix RHSA-2026:8945
  • Red Hat Enterprise Linux AppStream (v. 9) freerdp 2.11.7-1.el9_7.6, freerdp 2.11.7-7.el9_8.1, libwinpr 2.11.7-1.el9_7.6, libwinpr 2.11.7-7.el9_8.1, freerdp-libs 2.11.7-1.el9_7.6, freerdp-libs 2.11.7-7.el9_8.1
    fixed: vendor fix RHSA-2026:8457
  • Red Hat Enterprise Linux AppStream (v. 10) freerdp 3.10.3-5.el10_1.6, freerdp 3.10.3-12.el10_2.2, libwinpr 3.10.3-5.el10_1.6, libwinpr 3.10.3-12.el10_2.2, freerdp-libs 3.10.3-5.el10_1.6, freerdp-libs 3.10.3-12.el10_2.2
    fixed: vendor fix RHSA-2026:8458
  • Red Hat Enterprise Linux AppStream AUS (v. 8.2) freerdp 2.0.0-46.rc4.el8_2.11, libwinpr 2.0.0-46.rc4.el8_2.11, freerdp-libs 2.0.0-46.rc4.el8_2.11
    fixed: vendor fix RHSA-2026:11651
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) freerdp 2.2.0-13.el8_4, libwinpr 2.2.0-13.el8_4, freerdp-libs 2.2.0-13.el8_4
    fixed: vendor fix RHSA-2026:11649
show 14 more
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) freerdp 2.2.0-7.el8_6.6, libwinpr 2.2.0-7.el8_6.6, freerdp-libs 2.2.0-7.el8_6.6 Red Hat Enterprise Linux AppStream E4S (v.8.6) freerdp 2.2.0-7.el8_6.6, libwinpr 2.2.0-7.el8_6.6, freerdp-libs 2.2.0-7.el8_6.6
    fixed: vendor fix RHSA-2026:12388
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) freerdp 2.2.0-12.el8_8.6, libwinpr 2.2.0-12.el8_8.6, freerdp-libs 2.2.0-12.el8_8.6
    fixed: vendor fix RHSA-2026:12359
  • Red Hat Enterprise Linux AppStream E4S (v.9.0) freerdp 2.4.1-3.el9_0.5, libwinpr 2.4.1-3.el9_0.5, freerdp-libs 2.4.1-3.el9_0.5
    fixed: vendor fix RHSA-2026:11332
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) freerdp 2.4.1-6.el9_2.7, libwinpr 2.4.1-6.el9_2.7, freerdp-libs 2.4.1-6.el9_2.7
    fixed: vendor fix RHSA-2026:11336
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) freerdp 3.10.3-3.el10_0.6, libwinpr 3.10.3-3.el10_0.6, freerdp-libs 3.10.3-3.el10_0.6
    fixed: vendor fix RHSA-2026:11333
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) freerdp 2.11.2-1.el9_4.6, libwinpr 2.11.2-1.el9_4.6, freerdp-libs 2.11.2-1.el9_4.6
    fixed: vendor fix RHSA-2026:10709
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) freerdp 2.11.7-1.el9_6.8, libwinpr 2.11.7-1.el9_6.8, freerdp-libs 2.11.7-1.el9_6.8
    fixed: vendor fix RHSA-2026:9656
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) freerdp 2.2.0-13.el8_4, libwinpr 2.2.0-13.el8_4, freerdp-libs 2.2.0-13.el8_4
    fixed: vendor fix RHSA-2026:11649
  • Red Hat Enterprise Linux AppStream TUS (v.8.6) freerdp 2.2.0-7.el8_6.6, libwinpr 2.2.0-7.el8_6.6, freerdp-libs 2.2.0-7.el8_6.6
    fixed: vendor fix RHSA-2026:12388
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) freerdp 2.2.0-12.el8_8.6, libwinpr 2.2.0-12.el8_8.6, freerdp-libs 2.2.0-12.el8_8.6
    fixed: vendor fix RHSA-2026:12359
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) freerdp-devel 2.11.7-1.el9_7.6, freerdp-devel 2.11.7-7.el9_8.1, libwinpr-devel 2.11.7-1.el9_7.6, libwinpr-devel 2.11.7-7.el9_8.1, freerdp-debuginfo 2.11.7-1.el9_7.6, freerdp-debuginfo 2.11.7-7.el9_8.1, +6 more
    fixed: vendor fix RHSA-2026:8457
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) freerdp-server 3.10.3-5.el10_1.6, freerdp-server 3.10.3-12.el10_2.2
    fixed: vendor fix RHSA-2026:8458
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) freerdp-server 3.10.3-3.el10_0.6
    fixed: vendor fix RHSA-2026:11333
  • Red Hat Enterprise Linux CRB (v. 8) freerdp-devel 2.11.7-7.el8_10, freerdp-debuginfo 2.11.7-7.el8_10, libwinpr-debuginfo 2.11.7-7.el8_10, freerdp-debugsource 2.11.7-7.el8_10, freerdp-libs-debuginfo 2.11.7-7.el8_10
    fixed: vendor fix RHSA-2026:8945

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

0.40% chance of exploitation in the next 30 days, higher than 34% 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 10.0 Extended Update 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
  • Red Hat Red Hat Enterprise Linux 7

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.