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Fencer Vulns
high 7.5

CVE-2026-67298 json

FreeRDP 3.28.0 Heap Buffer Overflow via RAIL orderLength Underflow

published 2026-08-01 3 mo ago modified 2026-11-03 5 d ago also EUVD-2026-51824

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 54%
public exploits
0
none known

Summary

FreeRDP versions 3.28.0 and earlier contain a heap buffer overflow in the server-side RAIL channel handler (rail_server_handle_messages() in channels/rail/server/rail_main.c). When processing a RAIL PDU header, the code subtracts RAIL_PDU_HEADER_LENGTH from the peer-controlled orderLength field without first verifying orderLength is at least the header length. For orderLength values 0..3 this causes an unsigned integer underflow to a very large size, which bypasses the Stream_EnsureRemainingCapacity() capacity check (due to pointer arithmetic wraparound) and is then passed to WTSVirtualChannelRead(), resulting in an out-of-bounds heap write. A malicious or compromised RDP client can exploit this to corrupt the heap and crash the server. Fixed in FreeRDP 3.29.0.

Patch / fix

  • FreeRDP FreeRDP 3.29.0
  • freerdp3 Debian 14 3.29.0+dfsg-1

debian advisories DEBIAN-CVE-2026-67298

  • 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-2026-67298

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 10.2 2:3.10.3-12.el10_2.10
  • libwinpr RHEL 10.2 2:3.10.3-12.el10_2.10
  • freerdp-libs RHEL 10.2 2:3.10.3-12.el10_2.10
  • freerdp-server RHEL 10.2 2:3.10.3-12.el10_2.10
  • freerdp enterprise linux eus 10.0 2:3.10.3-3.el10_0.16
  • libwinpr enterprise linux eus 10.0 2:3.10.3-3.el10_0.16
  • freerdp-libs enterprise linux eus 10.0 2:3.10.3-3.el10_0.16
  • freerdp-server enterprise linux eus 10.0 2:3.10.3-3.el10_0.16

red hat advisories RHSA-2026:68706RHSA-2026:68707RHSA-2026:61378

  • 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

almalinux advisories ALSA-2026:61378

  • freerdp Rocky Linux 10 2:3.10.3-12.el10_2.10

rocky linux advisories RLSA-2026:61378

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-2026-67298 updated cvss 7.1

FreeRDP: FreeRDP: Denial of Service via integer underflow in RAIL channel handling

  • Red Hat Enterprise Linux 6 freerdp, freerdp-libs, freerdp-plugins
    affected: workaround, no fix planned “Out of support scope”
  • 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 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 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 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 8 freerdp, libwinpr, freerdp-libs
    not affected: vulnerable code not present
  • 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
partial
Assessed
3 mo ago

Exploit prediction

0.72% chance of exploitation in the next 30 days, higher than 54% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-5wr6-8m8j-3h7f referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qmvw-52ph-q5pv 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:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/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

Affected products

  • FreeRDP FreeRDP

Classification

Weakness
  • CWE-191 Integer Underflow (Wrap or Wraparound)

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.