Heap-based buffer overflow in FreeRDP - CVE-2026-55193

CSH
CYBERSECURITY HELP
Sign In REGISTER
 
Main Vulnerability Database Vulnerabilities #VU134506

Heap-based buffer overflow in FreeRDP - CVE-2026-55193

Published: June 15, 2026 / Updated: August 21, 2026


Vulnerability identifier: #VU134506
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-55193
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to heap-based buffer overflow in the TS Gateway RPC fragment receive logic when processing RESPONSE fragments from a TS Gateway after RPC bind negotiation. A remote attacker can send a crafted bind_ack and subsequent oversized RESPONSE fragments to execute arbitrary code.

The issue affects FreeRDP clients using TS Gateway / RD Gateway transport, and can also be triggered by an active machine-in-the-middle on gateway traffic. Direct RDP connections that do not use the gateway RPC layer are not affected.


Affected software

FreeRDP
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux Server - TUS
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support
Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support
Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support
Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Fedora
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
freerdp (Red Hat package)
freerdp

How to mitigate CVE-2026-55193

Install security update from vendor's website.

FreeRDP - update to 3.27.0
freerdp (Red Hat package) - addressed in versions 2.2.0-7.el8_6.13, 2.2.0-12.el8_8.12, 2.2.0-14.el8_4.4, 2.4.1-6.el9_2.13, 2.11.2-1.el9_4.12, 2.11.7-1.el9_6.14, 3.10.3-3.el10_0.18, 3.10.3-12.el10_2.11
freerdp - addressed in versions 3.27.1-1.fc43, 3.27.1-1.fc44

External References

Related Security Bulletins