CVE-2026-115866

Full vulnerability record from the local CVENow database.

Description

Starlet versions from 0.20 before 0.33 for Perl allow CPU exhaustion via regular expression backtracking when decoding chunked request bodies. A chunk-size line is matched as a run of hex digits, then .* and a CRLF. A run followed by a bare LF and then a CRLF can never match, and the engine retries the match once for each digit, so the time taken grows with the square of the run length. Nothing limits the length of the run, which can span several reads. A remote attacker can occupy a worker for about a minute of CPU time with one 128 KiB request, before the application is called.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

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

Published

2026-10-30 13:18:31.070000

Last modified

2026-10-30 13:18:31.070000

View original CVE JSON

{
  "id": "CVE-2026-115866",
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
  "published": "2026-10-30T13:18:31.070",
  "lastModified": "2026-10-30T13:18:31.070",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Starlet versions from 0.20 before 0.33 for Perl allow CPU exhaustion via regular expression backtracking when decoding chunked request bodies.\n\nA chunk-size line is matched as a run of hex digits, then .* and a CRLF. A run followed by a bare LF and then a CRLF can never match, and the engine retries the match once for each digit, so the time taken grows with the square of the run length. Nothing limits the length of the run, which can span several reads.\n\nA remote attacker can occupy a worker for about a minute of CPU time with one 128 KiB request, before the application is called."
    }
  ],
  "affected": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "collectionURL": "https://cpan.org/modules",
          "packageName": "Starlet",
          "modules": [
            "Starlet"
          ],
          "programFiles": [
            "lib/Starlet/Server.pm"
          ],
          "programRoutines": [
            {
              "name": "Starlet::Server::handle_connection"
            }
          ],
          "repo": "https://github.com/kazuho/Starlet",
          "packageURL": "pkg:cpan/Starlet",
          "versions": [
            {
              "version": "0.20",
              "lessThan": "0.33",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "weaknesses": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-1333"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/kazuho/Starlet/commit/229ea56b3b50028e2a644156317e8d0e7cf68a1f.patch",
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    },
    {
      "url": "https://metacpan.org/release/KAZUHO/Starlet-0.33/changes",
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    }
  ]
}