Vulnerability Description
Rouille 0.4.0 through 3.6.2 contains an HTTP response splitting vulnerability that allows remote attackers to inject arbitrary response headers by embedding carriage return (0x0D) or line feed (0x0A) bytes into attacker-controlled input. Attackers can exploit percent-decoded query parameters reflected into response headers or inject bare LF characters into Cookie header values that are interpolated directly into Set-Cookie response headers, enabling cache poisoning, session fixation, and security header override attacks such as bypassing CSP or CORS policies.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/theopaid/HTTP-Response-Splitting-via-Unvalidated-Response-Hea
- https://www.vulncheck.com/advisories/rouille-http-response-splitting-via-header-
FAQ
What is CVE-2026-66746?
CVE-2026-66746 is a vulnerability with a CVSS score of 5.4 (MEDIUM). Rouille 0.4.0 through 3.6.2 contains an HTTP response splitting vulnerability that allows remote attackers to inject arbitrary response headers by embedding carriage return (0x0D) or line feed (0x0A) ...
How severe is CVE-2026-66746?
CVE-2026-66746 has been rated MEDIUM with a CVSS base score of 5.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-66746?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.