CPU exhaustion via O(n^2) BigInt construction on radix-prefixed integer literals

{
  "id": "346b0fd1a60573c112ca9b7787a70a70bc2a1a95789c298995044d422d39a42a",
  "url": "https://osv.dev/vulnerability/CVE-2026-49293",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CPU exhaustion via O(n^2) BigInt construction on radix-prefixed integer literals",
    "summary": "js-toml is a TOML parser for JavaScript, fully compliant with the TOML 1.0.0 Spec. Versions up to and including 1.1.0 parse hexadecimal / octal / binary integer literals via a hand-written `parseBigInt` loop that multiplies a `BigInt` accumulator by the radix once per input digit. Each iteration performs a `BigInt * BigInt` operation on an accumulator that grows linearly with the number of digits already consumed, so the whole loop is O(n²) in the literal length. The lexer regex places no upper bound on the literal length, so a single TOML document containing one ~500 kB hex literal pins one CPU core for ~40 seconds on a modern laptop (Apple M-series, Node v22). Memory amplification is bounded but CPU amplification is severe and grows quadratically: doubling the literal length quadruples the work. A caller that invokes `load()` on attacker-controlled TOML (configuration upload endpoints, CI/CD systems ingesting third-party `*.toml`, IDE plugins, build tools) is exposed to a single-request CPU exhaustion DoS. Version 1.1.1 fixes the issue.",
    "evidence": "osv:CVE-2026-49293",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-49293",
      "aliases": [
        "CVE-2026-49293",
        "GHSA-wp3c-266w-4qfq"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/sunnyadn/js-toml",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "60d0741b59f8ae0699c0e0f04ca004f04302bcac"
                },
                {
                  "fixed": "1abcb31dc7b1fa88e4c848a8d108891cfbb96fa2"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:sunnyadn:js-toml:*:*:*:*:*:node.js:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.1.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "1abcb31dc7b1fa88e4c848a8d108891cfbb96fa2"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "60d0741b59f8ae0699c0e0f04ca004f04302bcac"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.1.1"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.1.0",
            "v1.0.3",
            "v1.0.2",
            "v1.0.1",
            "v1.0.0",
            "v0.1.1",
            "v0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49293.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:36.977628993Z",
      "provider": "osv",
      "references": [
        "https://github.com/sunnyadn/js-toml/releases/tag/v1.1.1",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49293.json",
        "https://github.com/sunnyadn/js-toml/security/advisories/GHSA-wp3c-266w-4qfq",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-49293",
        "https://github.com/sunnyadn/js-toml/commit/1abcb31dc7b1fa88e4c848a8d108891cfbb96fa2"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-1333",
          "CWE-400",
          "CWE-407"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49293.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-49293",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 504392,
  "published_at": "2026-06-19T18:14:20.15+00:00"
}