{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:kazuho:starlet:*:*:*:*:*:perl:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "0.31"
              }
            ],
            "source": [
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "a7d5dfd1862aafa43e5eaca0fdb6acf4cc15b2d0"
            }
          ],
          "repo": "https://github.com/kazuho/starlet",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "CPANSec",
    "cwe_ids": [
      "CWE-444"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40561.json"
  },
  "details": "Starlet versions through 0.31 for Perl allows HTTP Request Smuggling via Improper Header Precedence.\n\nStarlet 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.\n\nAn attacker could exploit this to smuggle malicious HTTP requests via a front-end reverse proxy.",
  "id": "CVE-2026-40561",
  "modified": "2026-07-08T05:36:29.532230575Z",
  "published": "2026-05-03T00:57:31.519Z",
  "references": [
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/05/03/1"
    },
    {
      "type": "WEB",
      "url": "https://cpan.org/modules"
    },
    {
      "type": "WEB",
      "url": "https://datatracker.ietf.org/doc/html/rfc7230#section-3.3.3"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40561.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://metacpan.org/release/KAZUHO/Starlet-0.32/changes"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40561"
    },
    {
      "type": "FIX",
      "url": "https://github.com/kazuho/Starlet/commit/a7d5dfd1862aafa43e5eaca0fdb6acf4cc15b2d0.patch"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/kazuho/Starlet"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Starlet versions through 0.31 for Perl allows HTTP Request Smuggling via Improper Header Precedence"
}