CVE-2026-40560

High

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.

SeverityHigh

CVSS7.5

Exploit probability—

ProductMiyagawa Starman

PublishedApr 29, 2026

First seenApr 29, 2026

Weakness typeCWE-444CWE-444

How to fix

Update

miyagawa starman0.4018 or later

Patches

github.com/miyagawa/Starman/commit/ced205f0805027e9d9c0731f8c40b104220604ed.patch

Vendor advisories

metacpan.org/release/MIYAGAWA/Starman-0.4018/changes

Affected products

Product	Affected versions	Fixed in
miyagawa starman	v < 0.4018	0.4018

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