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Fencer Vulns
high 8.8

CVE-2026-55193 json

FreeRDP: Heap-buffer-overflow write in TS Gateway RPC fragment receive due to uncapped bind_ack max_xmit_frag

published 2026-08-19 2 mo ago modified 2026-10-26 14 d ago also EUVD-2026-62664

cvss
8.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, FreeRDP clients using TS Gateway accept a server-controlled max_xmit_frag value in libfreerdp/core/gateway/rpc_bind.c without bounding it to the 4088-byte ReceiveFragment allocation. A malicious gateway can advertise 65535 and then send a response fragment of the same length, causing rpc_channel_read in libfreerdp/core/gateway/rpc.c to write up to 65535 bytes into the smaller ReceiveFragment buffer. This can crash the client and may permit code execution through attacker-controlled 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-2026-55193

  • 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-2026-55193

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 2:2.11.7-13.el8_10
  • libwinpr RHEL 8 2:2.11.7-13.el8_10
  • freerdp-libs RHEL 8 2:2.11.7-13.el8_10
  • freerdp RHEL 10.2 2:3.10.3-12.el10_2.11
  • libwinpr RHEL 10.2 2:3.10.3-12.el10_2.11
  • freerdp-libs RHEL 10.2 2:3.10.3-12.el10_2.11
  • freerdp-server RHEL 10.2 2:3.10.3-12.el10_2.11
  • freerdp RHEL 9 2:2.11.7-7.el9_8.7

red hat advisories RHSA-2026:74610RHSA-2026:74471RHSA-2026:74470RHSA-2026:73068RHSA-2026:73027RHSA-2026:73026

  • freerdp openSUSE Tumbleweed 3.27.1-1.1

opensuse advisories openSUSE-SU-2026:11065-1

  • freerdp AlmaLinux 8 2:2.11.7-13.el8_10
  • libwinpr AlmaLinux 8 2:2.11.7-13.el8_10
  • freerdp-libs AlmaLinux 8 2:2.11.7-13.el8_10
  • freerdp AlmaLinux 9 2:2.11.7-7.el9_8.7
  • libwinpr AlmaLinux 9 2:2.11.7-7.el9_8.7
  • freerdp-libs AlmaLinux 9 2:2.11.7-7.el9_8.7
  • freerdp AlmaLinux 10 2:3.10.3-12.el10_2.11
  • libwinpr AlmaLinux 10 2:3.10.3-12.el10_2.11

almalinux advisories ALSA-2026:69387ALSA-2026:66347ALSA-2026:66349

  • freerdp Rocky Linux 8 2:2.11.7-13.el8_10
  • freerdp Rocky Linux 10 2:3.10.3-12.el10_2.11
  • freerdp Rocky Linux 9 2:2.11.7-7.el9_8.7

rocky linux advisories RLSA-2026:69387RLSA-2026:66349RLSA-2026:66347

  • freerdp Alpine 3.24 3.27.1-r0

alpine advisories ALPINE-CVE-2026-55193

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-2026-55193 updated cvss 8.8

FreeRDP: FreeRDP: Remote code execution or client crash via malicious TS Gateway

  • Red Hat Enterprise Linux 6 freerdp, freerdp-libs, freerdp-plugins
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat CodeReady Linux Builder EUS (v.9.6) freerdp-devel 2.11.7-1.el9_6.14, libwinpr-devel 2.11.7-1.el9_6.14, freerdp-debuginfo 2.11.7-1.el9_6.14, libwinpr-debuginfo 2.11.7-1.el9_6.14, freerdp-debugsource 2.11.7-1.el9_6.14, freerdp-libs-debuginfo 2.11.7-1.el9_6.14
    fixed: vendor fix RHSA-2026:72479
  • Red Hat Enterprise Linux AppStream (v. 8) freerdp 2.11.7-13.el8_10, libwinpr 2.11.7-13.el8_10, freerdp-libs 2.11.7-13.el8_10
    fixed: vendor fix RHSA-2026:69387
  • Red Hat Enterprise Linux AppStream (v. 9) freerdp 2.11.7-7.el9_8.7, libwinpr 2.11.7-7.el9_8.7, freerdp-libs 2.11.7-7.el9_8.7
    fixed: vendor fix RHSA-2026:66347
  • Red Hat Enterprise Linux AppStream (v. 10) freerdp 3.10.3-12.el10_2.11, libwinpr 3.10.3-12.el10_2.11, freerdp-libs 3.10.3-12.el10_2.11
    fixed: vendor fix RHSA-2026:66349
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) freerdp 2.2.0-14.el8_4.4, libwinpr 2.2.0-14.el8_4.4, freerdp-libs 2.2.0-14.el8_4.4
    fixed: vendor fix RHSA-2026:73026
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) freerdp 2.2.0-7.el8_6.13, libwinpr 2.2.0-7.el8_6.13, freerdp-libs 2.2.0-7.el8_6.13
    fixed: vendor fix RHSA-2026:73027
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) freerdp 2.2.0-12.el8_8.12, libwinpr 2.2.0-12.el8_8.12, freerdp-libs 2.2.0-12.el8_8.12
    fixed: vendor fix RHSA-2026:73068
show 12 more
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) freerdp 2.4.1-6.el9_2.13, libwinpr 2.4.1-6.el9_2.13, freerdp-libs 2.4.1-6.el9_2.13
    fixed: vendor fix RHSA-2026:74470
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) freerdp 2.11.2-1.el9_4.12, libwinpr 2.11.2-1.el9_4.12, freerdp-libs 2.11.2-1.el9_4.12
    fixed: vendor fix RHSA-2026:72481
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) freerdp 3.10.3-3.el10_0.18, libwinpr 3.10.3-3.el10_0.18, freerdp-libs 3.10.3-3.el10_0.18
    fixed: vendor fix RHSA-2026:74471
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) freerdp 2.11.7-1.el9_6.14, libwinpr 2.11.7-1.el9_6.14, freerdp-libs 2.11.7-1.el9_6.14
    fixed: vendor fix RHSA-2026:72479
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) freerdp 2.2.0-14.el8_4.4, libwinpr 2.2.0-14.el8_4.4, freerdp-libs 2.2.0-14.el8_4.4
    fixed: vendor fix RHSA-2026:73026
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) freerdp 2.2.0-7.el8_6.13, libwinpr 2.2.0-7.el8_6.13, freerdp-libs 2.2.0-7.el8_6.13
    fixed: vendor fix RHSA-2026:73027
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) freerdp 2.2.0-12.el8_8.12, libwinpr 2.2.0-12.el8_8.12, freerdp-libs 2.2.0-12.el8_8.12
    fixed: vendor fix RHSA-2026:73068
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) freerdp-devel 2.11.7-7.el9_8.7, libwinpr-devel 2.11.7-7.el9_8.7, freerdp-debuginfo 2.11.7-7.el9_8.7, libwinpr-debuginfo 2.11.7-7.el9_8.7, freerdp-debugsource 2.11.7-7.el9_8.7, freerdp-libs-debuginfo 2.11.7-7.el9_8.7
    fixed: vendor fix RHSA-2026:66347
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) freerdp-server 3.10.3-12.el10_2.11
    fixed: vendor fix RHSA-2026:66349
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) freerdp-server 3.10.3-3.el10_0.18
    fixed: vendor fix RHSA-2026:74471
  • Red Hat Enterprise Linux CRB (v. 8) freerdp-devel 2.11.7-13.el8_10, freerdp-debuginfo 2.11.7-13.el8_10, libwinpr-debuginfo 2.11.7-13.el8_10, freerdp-debugsource 2.11.7-13.el8_10, freerdp-libs-debuginfo 2.11.7-13.el8_10
    fixed: vendor fix RHSA-2026:69387
  • Red Hat Enterprise Linux Server (v. 7 ELS) freerdp 2.1.1-5.el7_9.13, libwinpr 2.1.1-5.el7_9.13, freerdp-libs 2.1.1-5.el7_9.13 Red Hat Enterprise Linux Server Optional (v. 7 ELS) freerdp-devel 2.1.1-5.el7_9.13, libwinpr-devel 2.1.1-5.el7_9.13, freerdp-debuginfo 2.1.1-5.el7_9.13
    fixed: vendor fix RHSA-2026:74610

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

0.48% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-7rp4-66mc-j9vx 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 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

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.