CVE-2026-40561

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.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://datatracker.ietf.org/doc/html/rfc7230#section-3.3.3	Third Party Advisory
https://github.com/kazuho/Starlet/commit/a7d5dfd1862aafa43e5eaca0fdb6acf4cc15b2d0.patch	Patch
https://metacpan.org/release/KAZUHO/Starlet-0.32/changes
http://www.openwall.com/lists/oss-security/2026/05/03/1	Mailing List Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:kazuho:starlet:*:*:*:*:*:perl:*:*

History

No history.

Information

Published : 2026-05-03 01:15

Updated : 2026-06-17 10:45

NVD link : CVE-2026-40561

Mitre link : CVE-2026-40561

CVE.ORG link : CVE-2026-40561

JSON object : View

Products Affected

kazuho

starlet

CWE

CWE-444

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

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