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Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies

Type: advisorySources: Official CVE List

Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies. Starman decodes chunked request bodies before calling the application, matching each chunk-size line with `s/^(([0-9a-fA-F]+).*\015\012)//`. A line of hex digits followed by a bare LF and then CRLF never matches, because `.` does not match LF, and each failed attempt backtracks in time quadratic in the length of the hex run. Nothing limits the length of the line. A remote attacker can exhaust worker CPU by sending such requests to any route.

Products: Not specified
Affected versions: Not specified
Fixed versions: Not specified
CVEs: CVE-2026-115822
Confirmed fixed CVEs: Not specified
Updated in this feed: 28 Oct 2026, 21:38 UTC · Revision 1

Source evidence

Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies

core-cve · Original source

Published 25 Oct 2026, 16:51 UTC

cve:CVE-2026-115822

Complete source record

{
  "id": "c26a0c522ffadea1aa77f099420f3e4a507075ad5366674a3960f04c35a6e294",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-115822",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies",
    "summary": "Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies. Starman decodes chunked request bodies before calling the application, matching each chunk-size line with `s/^(([0-9a-fA-F]+).*\\015\\012)//`. A line of hex digits followed by a bare LF and then CRLF never matches, because `.` does not match LF, and each failed attempt backtracks in time quadratic in the length of the hex run. Nothing limits the length of the line. A remote attacker can exhaust worker CPU by sending such requests to any route.",
    "evidence": "cve:CVE-2026-115822",
    "products": [],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-115822",
      "aliases": [
        "CVE-2026-115822"
      ],
      "metrics": [],
      "affected": [
        {
          "repo": "https://github.com/miyagawa/Starman",
          "modules": [
            "Starman"
          ],
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "lessThan": "0.4019",
              "versionType": "custom"
            }
          ],
          "packageURL": "pkg:cpan/Starman",
          "packageName": "Starman",
          "programFiles": [
            "lib/Starman/Server.pm"
          ],
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "programRoutines": [
            {
              "name": "Starman::Server::_prepare_env"
            }
          ]
        }
      ],
      "modified": "2026-10-25T16:51:00.241Z",
      "provider": "cve",
      "references": [
        "https://github.com/miyagawa/Starman/commit/0f33f9b132b5e410d6cce722ff71988e22476acf.patch",
        "https://metacpan.org/release/MIYAGAWA/Starman-0.4019/changes"
      ],
      "provider_metadata": {
        "cna": {
          "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
          "shortName": "CPANSec",
          "dateUpdated": "2026-10-25T16:51:00.241Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-115822",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-cve",
  "document_id": 171999,
  "published_at": "2026-10-25T16:51:00.241+00:00"
}