CVE-2026-40561

Published: May 3, 2026Modified: Jun 17, 2026

5.3

Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Exploitability: 3.9 / Impact: 1.4

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

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.

Affected (1)

Products: Kazuho: Starlet

1 product

Configuration A

1 vulnerable

Vulnerable Software	Affected Versions
Kazuho Starlet	Up to 0.31

Related CWEs

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

References (4)

https://datatracker.ietf.org/doc/html/rfc7230#section-3.3.3

Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e

Third Party Advisory

https://github.com/kazuho/Starlet/commit/a7d5dfd1862aafa43e5eaca0fdb6acf4cc15b2d0.patch

Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e

Patch

https://metacpan.org/release/KAZUHO/Starlet-0.32/changes

Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e

http://www.openwall.com/lists/oss-security/2026/05/03/1

Source: af854a3a-2127-422b-91ae-364da2661108

Mailing ListThird Party Advisory

Timeline

No history available yet.