Vulnerability · Published May 6, 2026 · Assigned by CPANSec
CVE-2026-40562Gazelle versions through 0.49 for Perl allows HTTP Request Smuggling via Improper Header Precedence
High 7.5
In plain English
A high-severity security flaw in Gazelle from KAZEBURO. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities).
Official 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.
Affected products (as reported)
Weakness: CWE-444 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N