Vulnerability Description
Dancer2 versions before 2.2.0 for Perl do not strip CR and LF from response header names in headers_to_array. The routine removes CR and LF from each header value but not from the name. A name carrying them therefore reaches the PSGI server intact. A server that does not validate keys writes it to the wire, so the bytes after the CRLF arrive as their own header line. The application has to derive the header name from request data, not just the value. An attacker who controls that data adds their own headers and splits the response.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/PerlDancer/Dancer2/commit/ff89ac12af7b8899812a79e9924dfea7a5d
- https://github.com/PerlDancer/Dancer2/issues/1822
- https://metacpan.org/release/CROMEDOME/Dancer2-2.2.0/changes
- http://www.openwall.com/lists/oss-security/2026/09/22/3
FAQ
What is CVE-2026-93711?
CVE-2026-93711 is a vulnerability with a CVSS score of 6.5 (MEDIUM). Dancer2 versions before 2.2.0 for Perl do not strip CR and LF from response header names in headers_to_array. The routine removes CR and LF from each header value but not from the name. A name carryi...
How severe is CVE-2026-93711?
CVE-2026-93711 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-93711?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.