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Fencer Vulns
critical 9.8

CVE-2026-55194 json

FreeRDPHeap-buffer-overflow write in TS Gateway RPC RESPONSE reassembly due to alloc_hint capacity mismatch

published 2026-08-19 2 mo ago modified 2026-10-26 14 d ago also EUVD-2026-62667

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits
0
none known

Summary

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, rpc_client_recv_fragment in libfreerdp/core/gateway/rpc_client.c ensures the response reassembly stream capacity using only the server-declared alloc_hint rather than the actual StubLength about to be written. A malicious TS Gateway can send a PTYPE_RESPONSE with a small alloc_hint and a much larger frag_length, causing Stream_Write to copy attacker-controlled stub data beyond the 4096-byte pdu->s buffer. This can crash the client and may permit code execution through heap corruption. 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-2026-55194

  • 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-2026-55194

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 8 2:2.11.7-12.el8_10
  • libwinpr RHEL 8 2:2.11.7-12.el8_10
  • freerdp-libs RHEL 8 2:2.11.7-12.el8_10
  • freerdp RHEL 9 2:2.11.7-7.el9_8.6
  • libwinpr RHEL 9 2:2.11.7-7.el9_8.6
  • freerdp-libs RHEL 9 2:2.11.7-7.el9_8.6
  • freerdp RHEL 10.2 2:3.10.3-12.el10_2.10
  • libwinpr RHEL 10.2 2:3.10.3-12.el10_2.10

red hat advisories RHSA-2026:71390RHSA-2026:71388RHSA-2026:71387RHSA-2026:68706RHSA-2026:68707RHSA-2026:66281

  • freerdp openSUSE Tumbleweed 3.27.1-1.1

opensuse advisories openSUSE-SU-2026:11065-1

  • freerdp AlmaLinux 8 2:2.11.7-12.el8_10
  • libwinpr AlmaLinux 8 2:2.11.7-12.el8_10
  • freerdp-libs AlmaLinux 8 2:2.11.7-12.el8_10
  • freerdp AlmaLinux 10 2:3.10.3-12.el10_2.10
  • libwinpr AlmaLinux 10 2:3.10.3-12.el10_2.10
  • freerdp-libs AlmaLinux 10 2:3.10.3-12.el10_2.10
  • freerdp-server AlmaLinux 10 2:3.10.3-12.el10_2.10
  • freerdp AlmaLinux 9 2:2.11.7-7.el9_8.6

almalinux advisories ALSA-2026:62571ALSA-2026:61378ALSA-2026:61379

  • freerdp Rocky Linux 8 2:2.11.7-12.el8_10
  • freerdp Rocky Linux 10 2:3.10.3-12.el10_2.10
  • freerdp Rocky Linux 9 2:2.11.7-7.el9_8.6

rocky linux advisories RLSA-2026:62571RLSA-2026:61378RLSA-2026:61379

  • freerdp Alpine 3.24 3.27.1-r0

alpine advisories ALPINE-CVE-2026-55194

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-2026-55194 updated cvss 8.8

FreeRDP: FreeRDP: Heap-buffer-overflow allows arbitrary code execution via crafted RPC response

  • Red Hat CodeReady Linux Builder EUS (v.9.6) freerdp-devel 2.11.7-1.el9_6.13, libwinpr-devel 2.11.7-1.el9_6.13, freerdp-debuginfo 2.11.7-1.el9_6.13, libwinpr-debuginfo 2.11.7-1.el9_6.13, freerdp-debugsource 2.11.7-1.el9_6.13, freerdp-libs-debuginfo 2.11.7-1.el9_6.13
    fixed: vendor fix RHSA-2026:71387
  • Red Hat Enterprise Linux AppStream (v. 8) freerdp 2.11.7-12.el8_10, libwinpr 2.11.7-12.el8_10, freerdp-libs 2.11.7-12.el8_10
    fixed: vendor fix RHSA-2026:62571
  • Red Hat Enterprise Linux AppStream (v. 9) freerdp 2.11.7-7.el9_8.6, libwinpr 2.11.7-7.el9_8.6, freerdp-libs 2.11.7-7.el9_8.6
    fixed: vendor fix RHSA-2026:61379
  • Red Hat Enterprise Linux AppStream (v. 10) freerdp 3.10.3-12.el10_2.10, libwinpr 3.10.3-12.el10_2.10, freerdp-libs 3.10.3-12.el10_2.10
    fixed: vendor fix RHSA-2026:61378
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) freerdp 2.2.0-14.el8_4.3, libwinpr 2.2.0-14.el8_4.3, freerdp-libs 2.2.0-14.el8_4.3
    fixed: vendor fix RHSA-2026:65855
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) freerdp 2.2.0-7.el8_6.12, libwinpr 2.2.0-7.el8_6.12, freerdp-libs 2.2.0-7.el8_6.12
    fixed: vendor fix RHSA-2026:66281
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) freerdp 2.2.0-12.el8_8.11, libwinpr 2.2.0-12.el8_8.11, freerdp-libs 2.2.0-12.el8_8.11
    fixed: vendor fix RHSA-2026:66282
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) freerdp 2.4.1-6.el9_2.12, libwinpr 2.4.1-6.el9_2.12, freerdp-libs 2.4.1-6.el9_2.12
    fixed: vendor fix RHSA-2026:71388
show 12 more
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) freerdp 2.11.2-1.el9_4.11, libwinpr 2.11.2-1.el9_4.11, freerdp-libs 2.11.2-1.el9_4.11
    fixed: vendor fix RHSA-2026:71390
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) freerdp 3.10.3-3.el10_0.16, libwinpr 3.10.3-3.el10_0.16, freerdp-libs 3.10.3-3.el10_0.16
    fixed: vendor fix RHSA-2026:68706
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) freerdp 2.11.7-1.el9_6.13, libwinpr 2.11.7-1.el9_6.13, freerdp-libs 2.11.7-1.el9_6.13
    fixed: vendor fix RHSA-2026:71387
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) freerdp 2.2.0-14.el8_4.3, libwinpr 2.2.0-14.el8_4.3, freerdp-libs 2.2.0-14.el8_4.3
    fixed: vendor fix RHSA-2026:65855
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) freerdp 2.2.0-7.el8_6.12, libwinpr 2.2.0-7.el8_6.12, freerdp-libs 2.2.0-7.el8_6.12
    fixed: vendor fix RHSA-2026:66281
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) freerdp 2.2.0-12.el8_8.11, libwinpr 2.2.0-12.el8_8.11, freerdp-libs 2.2.0-12.el8_8.11
    fixed: vendor fix RHSA-2026:66282
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) freerdp-devel 2.11.7-7.el9_8.6, libwinpr-devel 2.11.7-7.el9_8.6, freerdp-debuginfo 2.11.7-7.el9_8.6, libwinpr-debuginfo 2.11.7-7.el9_8.6, freerdp-debugsource 2.11.7-7.el9_8.6, freerdp-libs-debuginfo 2.11.7-7.el9_8.6
    fixed: vendor fix RHSA-2026:61379
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) freerdp-server 3.10.3-12.el10_2.10
    fixed: vendor fix RHSA-2026:61378
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) freerdp-server 3.10.3-3.el10_0.16
    fixed: vendor fix RHSA-2026:68706
  • Red Hat Enterprise Linux CRB (v. 8) freerdp-devel 2.11.7-12.el8_10, freerdp-debuginfo 2.11.7-12.el8_10, libwinpr-debuginfo 2.11.7-12.el8_10, freerdp-debugsource 2.11.7-12.el8_10, freerdp-libs-debuginfo 2.11.7-12.el8_10
    fixed: vendor fix RHSA-2026:62571
  • 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 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
2 mo ago

Exploit prediction

0.62% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9gxm-3mf5-f5cx referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/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 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • FreeRDP FreeRDP

Classification

Weakness
  • CWE-122 Heap-based Buffer Overflow

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.