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Fencer Vulns
high 8.2

CVE-2026-55192 json

FreeRDP: Out-of-bounds read in H.264 YUV-to-RGB conversion due to decoder/surface dimension mismatch

published 2026-08-19 2 mo ago modified 2026-10-26 13 d ago also EUVD-2026-62668

cvss
8.2
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 39%
public exploits
0
none known

Summary

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, FreeRDP H.264 decoder backends can return YUV planes sized from the bitstream without comparing the decoded width and height to the RDPGFX surface dimensions used to validate region rectangles. A malicious RDP server can provide an AVC420 or AVC444 bitstream whose decoded frame is smaller than the negotiated surface, causing yuv420_context_decode and the YUV-to-RGB conversion paths to read beyond the decoder-owned planes in libfreerdp/codec/h264.c and the selected H.264 backend. This can disclose client memory or crash the client. This issue is fixed in version 3.27.0.

Patch / fix

  • freerdp freerdp 3.27.0
  • freerdp3 Debian 14 3.27.0+dfsg-1

debian advisories DEBIAN-CVE-2026-55192

  • 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-2026-55192

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 7 ELS 2.1.1-5.el7_9.12
  • libwinpr RHEL 7 ELS 2.1.1-5.el7_9.12
  • freerdp-libs RHEL 7 ELS 2.1.1-5.el7_9.12

red hat advisories RHSA-2026:68707

  • freerdp openSUSE Tumbleweed 3.27.1-1.1

opensuse advisories openSUSE-SU-2026:11065-1

  • freerdp Alpine 3.24 3.27.1-r0

alpine advisories ALPINE-CVE-2026-55192

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-2026-55192 updated cvss 8.1

FreeRDP: FreeRDP: Out-of-bounds read leads to memory disclosure or client crash

  • Red Hat Enterprise Linux 10 freerdp
    affected: workaround, no fix available
  • Red Hat Enterprise Linux Server (v. 7 ELS) freerdp 2.1.1-5.el7_9.12, libwinpr 2.1.1-5.el7_9.12, freerdp-libs 2.1.1-5.el7_9.12 Red Hat Enterprise Linux Server Optional (v. 7 ELS) freerdp-devel 2.1.1-5.el7_9.12, libwinpr-devel 2.1.1-5.el7_9.12, freerdp-debuginfo 2.1.1-5.el7_9.12
    fixed: vendor fix RHSA-2026:68707
  • Red Hat Enterprise Linux 6 freerdp, freerdp-libs, freerdp-plugins
    not affected: vulnerable code not present
  • Red Hat Enterprise Linux 8 freerdp, libwinpr, freerdp-libs
    not affected: vulnerable code not in execute path
  • Red Hat Enterprise Linux 9 freerdp, libwinpr, freerdp-libs
    not affected: component 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
yes
Technical impact
total
Assessed
2 mo ago

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-3mmf-qh4f-frm6 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 7.2 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N
CNA 4.0 7.2 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

Affected products

  • FreeRDP FreeRDP

Classification

Weakness

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.