CVE-2026-93711
mediumDancer2 versions before 2.2.0 for Perl do not strip CR and LF from response header names in headers_to_array.
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/PerlDancer/Dancer2/commit/ff89ac12af7b8899812a79e9924dfea7a5d9833b.patc... 9b29abf9-4ab0-4765-b253-1875cd9b441e
- https://github.com/PerlDancer/Dancer2/issues/1822 9b29abf9-4ab0-4765-b253-1875cd9b441e
- https://metacpan.org/release/CROMEDOME/Dancer2-2.2.0/changes 9b29abf9-4ab0-4765-b253-1875cd9b441e
- http://www.openwall.com/lists/oss-security/2026/09/22/3 af854a3a-2127-422b-91ae-364da2661108