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GHSA-2826-QW6W-9H42

Vulnerability from github – Published: 2026-10-25 18:31 – Updated: 2026-10-25 18:31

Details

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.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-115822"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1333"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-25T17:17:01Z",
    "severity": null
  },
  "details": "Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies.\n\nStarman 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.\n\nA remote attacker can exhaust worker CPU by sending such requests to any route.",
  "id": "GHSA-2826-qw6w-9h42",
  "modified": "2026-10-25T18:31:41Z",
  "published": "2026-10-25T18:31:41Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-115822"
    },
    {
      "type": "WEB",
      "url": "https://github.com/miyagawa/Starman/commit/0f33f9b132b5e410d6cce722ff71988e22476acf.patch"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/MIYAGAWA/Starman-0.4019/changes"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-115822 (GCVE-0-2026-115822)

Vulnerability from cvelistv5 – Published: 2026-10-25 16:51 – Updated: 2026-10-25 16:51

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.

Severity

No CVSS data available.

CWE

CWE-1333 - Inefficient Regular Expression Complexity

Assigner

CPANSec CNA under the redhat root

CNA scorecard C 63/100 over 298 records in the last 180 days details

References

2 references

URL	Tags
https://github.com/miyagawa/Starman/commit/0f33f9…	patch
https://metacpan.org/release/MIYAGAWA/Starman-0.4…	release-notes

Impacted products

1 product

Vendor	Product	Version
		Affected: 0 , < 0.4019 (custom)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Starman"
          ],
          "packageName": "Starman",
          "packageURL": "pkg:cpan/Starman",
          "programFiles": [
            "lib/Starman/Server.pm"
          ],
          "programRoutines": [
            {
              "name": "Starman::Server::_prepare_env"
            }
          ],
          "repo": "https://github.com/miyagawa/Starman",
          "versions": [
            {
              "lessThan": "0.4019",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies.\n\nStarman 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.\n\nA remote attacker can exhaust worker CPU by sending such requests to any route."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1333",
              "description": "CWE-1333 Inefficient Regular Expression Complexity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-25T16:51:00.241Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/miyagawa/Starman/commit/0f33f9b132b5e410d6cce722ff71988e22476acf.patch"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://metacpan.org/release/MIYAGAWA/Starman-0.4019/changes"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to Starman 0.4019 or later."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Starman versions before 0.4019 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies",
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-115822",
    "datePublished": "2026-10-25T16:51:00.241Z",
    "dateReserved": "2026-10-23T16:47:20.192Z",
    "dateUpdated": "2026-10-25T16:51:00.241Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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