Out-of-bounds read in FreeRDP - CVE-2026-67291

Vulnerability identifier: #VU137828

CSH Severity: Medium

CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-67291

CWE-ID: CWE-125

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to out-of-bounds read in update_process_glyph_fragments() and glyph_cache_fragment_put() when processing GLYPH_FRAGMENT_ADD data from an RDP server. A remote attacker can send a short GLYPH_FRAGMENT_ADD payload with a larger declared fragment size to cause a denial of service.

The demonstrated impact is a client-side crash, and no attacker-controlled write primitive, remote code execution, or direct information disclosure beyond the out-of-bounds read was confirmed.

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

Install security update from vendor's website.

FreeRDP - update to 3.29.0
freerdp (Red Hat package) - addressed in versions 2.2.0-7.el8_6.12, 2.2.0-12.el8_8.11, 2.2.0-14.el8_4.3, 2.11.7-7.el9_8.6, 2.11.7-12.el8_10

• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-hgj8-g595-wfc6

• Multiple vulnerabilities in FreeRDP
• Red Hat Enterprise Linux 9 update for freerdp
• Red Hat Enterprise Linux 8 update for freerdp
• Red Hat Enterprise Linux 8 update for freerdp
• Red Hat Enterprise Linux 8 update for freerdp
• Red Hat Enterprise Linux 8 update for freerdp