{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:nodeca:js-yaml:*:*:*:*:*:node.js:*:*",
            "extracted_events": [
              {
                "introduced": "5.0.0"
              },
              {
                "fixed": "5.2.1"
              }
            ],
            "source": [
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "75148bc4f5eb69b3d338e1c355d8bb2dba5bdf34"
            },
            {
              "fixed": "ac16b42c46c11c5c7f66062bfc78b168b5f07ecd"
            },
            {
              "fixed": "39f3211a2f01b3c6982710cf21434ab7060acefe"
            }
          ],
          "repo": "https://github.com/nodeca/js-yaml",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-724g-mxrg-4qvm"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-407"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59870.json"
  },
  "details": "js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 before 5.2.1, YAML11_SCHEMA support for the !!omap tag in src/tag/sequence/omap.ts uses omapTag.addItem() to perform a linear duplicate-key scan on every insertion, causing O(n^2) CPU consumption when yaml.load() parses a crafted ordered-map document. This issue is fixed in version 5.2.1.",
  "id": "CVE-2026-59870",
  "modified": "2026-07-12T03:55:15.788736287Z",
  "published": "2026-07-08T15:13:20.308Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nodeca/js-yaml/releases/tag/5.2.1"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59870.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/nodeca/js-yaml/security/advisories/GHSA-724g-mxrg-4qvm"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59870"
    },
    {
      "type": "FIX",
      "url": "https://github.com/nodeca/js-yaml/commit/39f3211a2f01b3c6982710cf21434ab7060acefe"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "js-yaml quadratic-complexity denial of service via YAML11_SCHEMA !!omap parsing"
}