CVE-2026-40560

Name	CVE-2026-40560
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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1135229

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
starman (PTS)	bookworm	0.4016-1	vulnerable
	trixie	0.4018-0+deb13u1	fixed
	forky, sid	0.4018-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
starman	source	trixie	0.4018-0+deb13u1
starman	source	(unstable)	0.4018-1			1135229

Notes

[bookworm] - starman <no-dsa> (Minor issue; can be fixed via point release)
[bullseye] - starman <postponed> (Minor issue; can be fixed in next update)
https://lists.security.metacpan.org/cve-announce/msg/39426182/
Fixed by: https://github.com/miyagawa/Starman/commit/ced205f0805027e9d9c0731f8c40b104220604ed (0.4018)