CVE-2026-40561

MEDIUM

Starlet versions through 0.31 for Perl allows HTTP Request Smuggling via Improper Header Precedence

Title source: cna
STIX 2.1

Description

Starlet versions through 0.31 for Perl allows HTTP Request Smuggling via Improper Header Precedence. Starlet 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.

References (4)

Core 4

Scores

CVSS v3 5.3
EPSS 0.0001
EPSS Percentile 1.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-444
Status published
Products (2)
KAZUHO/Starlet < 0.31
kazuho/starlet < 0.31
Published May 03, 2026
Tracked Since May 03, 2026