CVE-2026-67289 (CVSS 9.8)

Description

FreeRDP before 3.29.0 (affected versions <= 3.28.0) does not validate CRLF and control characters in the server-controlled RDP redirection TargetNetAddress field. This value is copied into the client's ServerHostname and, when the client connects through an HTTP proxy, is written directly into the proxy CONNECT request line and Host header by http_proxy_connect() without filtering. A malicious or compromised RDP server can send a crafted redirection PDU containing embedded control characters to inject arbitrary headers/requests into the HTTP proxy CONNECT request.

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CVSS v3.1 Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0040

Probability of exploitation

0.33%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-113 CWE-113

References

Other References

https://github.com/FreeRDP/FreeRDP/commit/f3b4347105114fe7453828736bea069999af319f https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-mwwh-mhp9-q7vm https://www.vulncheck.com/advisories/freerdp-before-http-proxy-request-injection-via-redirection

Frequently Asked Questions

What is CVE-2026-67289? +

FreeRDP before 3.29.0 (affected versions <= 3.28.0) does not validate CRLF and control characters in the server-controlled RDP redirection TargetNetAddress field. This value is copied into the client's ServerHostname and, when the client connects through an HTTP proxy, is written directly into the proxy CONNECT request line and Host header by http_proxy_connect() without filtering. A malicious or compromised RDP server can send a crafted redirection PDU containing embedded control characters to inject arbitrary headers/requests into the HTTP proxy CONNECT request. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-67289? +

CVE-2026-67289 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0040, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-67289? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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