CVE-2026-40562

High

Description

Gazelle versions through 0.49 for Perl allows HTTP Request Smuggling via Improper Header Precedence. Gazelle 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—

ProductKazeburo Gazelle

PublishedMay 6, 2026

First seenMay 6, 2026

Weakness typeCWE-444CWE-444

How to fix

Update

kazeburo gazelle0.50 or later

Patches

security.metacpan.org/patches/G/Gazelle/0.49/CVE-2026-40562-r1.patch

Vendor advisories

metacpan.org/release/KAZEBURO/Gazelle-0.50/changes

Affected products

Product	Affected versions	Fixed in
kazeburo gazelle	v < 0.50	0.50

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