Description
Starman versions before 0.4018 for Perl allows HTTP Request Smuggling via Improper Header Precedence. Starman incorrectly prioritizes "Content-Length" over "Transfer-Encoding: chunked" when both headers are present in an HTTP request. Per RFC 7230 3.3.3, Transfer-Encoding must take precedence. An attacker could exploit this to smuggle malicious HTTP requests via a front-end reverse proxy.
Affected products
miyagawa: starman
References4
- github.com/miyagawa/Starman/commit/ced205f0805027e9d9c0731f8c40… PatchThird Party Advisory
- datatracker.ietf.org/doc/html/rfc7230#section-3.3.3 Third Party Advisory
- metacpan.org/release/MIYAGAWA/Starman-0.4018/changes ProductRelease Notes
- www.openwall.com/lists/oss-security/2026/04/29/1 Mailing ListThird Party Advisory
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - EPSS — exploit probability
- 0% percentile: 43 · as of 13 November 2026
- CWE
- CWE-444
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.