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.

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Fixes

Solution

No solution given by the vendor.


Workaround

Migrate to Starman 0.4018 or later which has fixed this issue or apply the patch.

History

Mon, 04 May 2026 16:15:00 +0000

Type Values Removed Values Added
First Time appeared Kazuho
Kazuho starlet
Vendors & Products Kazuho
Kazuho starlet

Mon, 04 May 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Sun, 03 May 2026 05:30:00 +0000

Type Values Removed Values Added
References

Sun, 03 May 2026 01:15:00 +0000

Type Values Removed Values Added
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.
Title Starlet versions through 0.31 for Perl allows HTTP Request Smuggling via Improper Header Precedence
Weaknesses CWE-444
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: CPANSec

Published:

Updated: 2026-05-04T13:54:47.941Z

Reserved: 2026-04-14T11:35:53.644Z

Link: CVE-2026-40561

cve-icon Vulnrichment

Updated: 2026-05-04T13:51:29.776Z

cve-icon NVD

Status : Received

Published: 2026-05-03T01:15:58.390

Modified: 2026-05-04T14:16:33.620

Link: CVE-2026-40561

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-04T16:06:41Z

Weaknesses