CVE-2026-59869 (GCVE-0-2026-59869)

Vulnerability from cvelistv5 – Published: 2026-07-08 15:15 – Updated: 2026-07-08 15:15
VLAI
Title
js-yaml: YAML merge-key chains can force quadratic CPU consumption
Summary
js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 before 3.15.0 and from 4.0.0 before 4.3.0, js-yaml can spend quadratic CPU time parsing a document whose size grows only linearly when a chain of mappings uses merge keys where each mapping merges the previous one. This issue is fixed in versions 3.15.0 and 4.3.0.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-407 - Inefficient Algorithmic Complexity
Assigner
References
Impacted products
Vendor Product Version
nodeca js-yaml Affected: >= 3.0.0, < 3.15.0
Affected: >= 4.0.0, < 4.3.0
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        }
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            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
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      "providerMetadata": {
        "dateUpdated": "2026-07-08T15:15:54.675Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/nodeca/js-yaml/security/advisories/GHSA-52cp-r559-cp3m",
          "tags": [
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          ],
          "url": "https://github.com/nodeca/js-yaml/security/advisories/GHSA-52cp-r559-cp3m"
        },
        {
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          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nodeca/js-yaml/commit/59423c6f8cdc78742ac00e25a4dd39ef16b702e4"
        },
        {
          "name": "https://github.com/nodeca/js-yaml/releases/tag/3.15.0",
          "tags": [
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        },
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          "tags": [
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          ],
          "url": "https://github.com/nodeca/js-yaml/releases/tag/4.3.0"
        }
      ],
      "source": {
        "advisory": "GHSA-52cp-r559-cp3m",
        "discovery": "UNKNOWN"
      },
      "title": "js-yaml: YAML merge-key chains can force quadratic CPU consumption"
    }
  },
  "cveMetadata": {
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    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-59869",
    "datePublished": "2026-07-08T15:15:54.675Z",
    "dateReserved": "2026-07-07T15:41:53.607Z",
    "dateUpdated": "2026-07-08T15:15:54.675Z",
    "state": "PUBLISHED"
  },
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  "dataVersion": "5.2",
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  }
}



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