Input validation error in FreeRDP - CVE-2026-67289
Published: July 16, 2026 / Updated: September 14, 2026
Vulnerability identifier: #VU137826
CSH Severity: Low
CVSS v4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-67289
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to inject headers into HTTP proxy CONNECT requests.
The vulnerability exists due to improper input validation in http_proxy_connect() when processing a server-controlled redirected TargetNetAddress through an HTTP proxy connection. A remote attacker can send a crafted redirection PDU containing CRLF or other control characters to inject headers into HTTP proxy CONNECT requests.
Exploitation requires the client to use an HTTP proxy and to connect to a malicious or compromised RDP server that can send a redirection PDU.
Affected software
FreeRDP
How to mitigate CVE-2026-67289
Install security update from vendor's website.
FreeRDP - update to 3.29.0