Vulnerability-Lookup

OESA-2026-4060 (CVE-2026-84375)

Vulnerability from osv_openeuler – Published: 2026-09-25 01:27 – Updated: 2026-09-25 01:27 – Source website

Summary

nodejs-js-yaml security update

Details

This is an implementation of YAML (YAML Ain't Markup Language), a human friendly data serialization language. It started as PyYAML port, and was completely rewritten from scratch. Now it's very fast, and supports the 1.2 spec.

Security Fix(es):

js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 until 3.15.2 and 4.3.2, maxTotalMergeKeys in lib/js-yaml/loader.js and lib/loader.js does not count empty mapping sources while processing the merge key <<. An attacker can alias a large sequence of empty mappings into many merge targets, causing O(N * K) processing while totalMergeKeys remains unchanged and the configured resource limit is never reached. A relatively small YAML document can therefore cause prolonged CPU consumption in applications that parse untrusted YAML, and merge processing is enabled by default on these release lines. This issue is fixed in versions 3.15.2 and 4.3.2.(CVE-2026-84375)

Severity

7.5 (High)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

URL

Type

	https://www.openeuler.org/zh/security/security-bu…	ADVISORY
	https://nvd.nist.gov/vuln/detail/CVE-2026-84375	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "noarch": [
          "nodejs-js-yaml-3.10.0-3.oe2403sp4.noarch.rpm"
        ],
        "src": [
          "nodejs-js-yaml-3.10.0-3.oe2403sp4.src.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:24.03-LTS-SP4",
        "name": "nodejs-js-yaml",
        "purl": "pkg:rpm/openEuler/nodejs-js-yaml\u0026distro=openEuler-24.03-LTS-SP4"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.10.0-3.oe2403sp4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "noarch": [
          "nodejs-js-yaml-3.10.0-3.oe2003sp4.noarch.rpm"
        ],
        "src": [
          "nodejs-js-yaml-3.10.0-3.oe2003sp4.src.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:20.03-LTS-SP4",
        "name": "nodejs-js-yaml",
        "purl": "pkg:rpm/openEuler/nodejs-js-yaml\u0026distro=openEuler-20.03-LTS-SP4"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.10.0-3.oe2003sp4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "noarch": [
          "nodejs-js-yaml-3.10.0-3.oe2203sp4.noarch.rpm"
        ],
        "src": [
          "nodejs-js-yaml-3.10.0-3.oe2203sp4.src.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:22.03-LTS-SP4",
        "name": "nodejs-js-yaml",
        "purl": "pkg:rpm/openEuler/nodejs-js-yaml\u0026distro=openEuler-22.03-LTS-SP4"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.10.0-3.oe2203sp4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "noarch": [
          "nodejs-js-yaml-3.10.0-3.oe2403sp1.noarch.rpm"
        ],
        "src": [
          "nodejs-js-yaml-3.10.0-3.oe2403sp1.src.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:24.03-LTS-SP1",
        "name": "nodejs-js-yaml",
        "purl": "pkg:rpm/openEuler/nodejs-js-yaml\u0026distro=openEuler-24.03-LTS-SP1"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.10.0-3.oe2403sp1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "noarch": [
          "nodejs-js-yaml-3.10.0-3.oe2403sp3.noarch.rpm"
        ],
        "src": [
          "nodejs-js-yaml-3.10.0-3.oe2403sp3.src.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:24.03-LTS-SP3",
        "name": "nodejs-js-yaml",
        "purl": "pkg:rpm/openEuler/nodejs-js-yaml\u0026distro=openEuler-24.03-LTS-SP3"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.10.0-3.oe2403sp3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "severity": "High"
  },
  "details": "This is an implementation of YAML (YAML Ain\u0026amp;apos;t Markup Language), a human friendly data serialization language. It started as PyYAML port, and was completely rewritten from scratch.  Now it\u0026amp;apos;s very fast, and supports the 1.2 spec.\r\n\r\nSecurity Fix(es):\n\njs-yaml is a JavaScript YAML parser and dumper. From 3.0.0 until 3.15.2 and 4.3.2, maxTotalMergeKeys in lib/js-yaml/loader.js and lib/loader.js does not count empty mapping sources while processing the merge key \u0026lt;\u0026lt;. An attacker can alias a large sequence of empty mappings into many merge targets, causing O(N * K) processing while totalMergeKeys remains unchanged and the configured resource limit is never reached. A relatively small YAML document can therefore cause prolonged CPU consumption in applications that parse untrusted YAML, and merge processing is enabled by default on these release lines. This issue is fixed in versions 3.15.2 and 4.3.2.(CVE-2026-84375)",
  "id": "OESA-2026-4060",
  "modified": "2026-09-25T01:27:53Z",
  "published": "2026-09-25T01:27:53Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4060"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-84375"
    }
  ],
  "schema_version": "1.7.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "nodejs-js-yaml security update",
  "upstream": [
    "CVE-2026-84375"
  ]
}

CVE-2026-84375 (GCVE-0-2026-84375)

Vulnerability from cvelistv5 – Published: 2026-09-01 21:43 – Updated: 2026-09-28 21:32

Title

js-yaml: maxTotalMergeKeys does not limit CPU use for empty merge sources

Summary

js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 until 3.15.2, 4.3.2, and 5.4.1, maxTotalMergeKeys in lib/js-yaml/loader.js and lib/loader.js does not count empty mapping sources while processing the merge key <<. An attacker can alias a large sequence of empty mappings into many merge targets, causing O(N * K) processing while totalMergeKeys remains unchanged and the configured resource limit is never reached. A relatively small YAML document can therefore cause prolonged CPU consumption in applications that parse untrusted YAML, and merge processing is enabled by default on these release lines. In v3 & v4, merge is enabled by default so the severity score is higher. This issue is fixed in versions 3.15.2, 4.3.2, and 5.4.1.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-02 13:43 UTC

CWE

CWE-400 - Uncontrolled Resource Consumption
CWE-407 - Inefficient Algorithmic Complexity

Assigner

GitHub_M mitre root

References

8 references

URL	Tags
https://github.com/nodeca/js-yaml/security/adviso…	x_refsource_CONFIRM
https://github.com/nodeca/js-yaml/pull/797	x_refsource_MISC
https://github.com/nodeca/js-yaml/commit/3485bc06…	x_refsource_MISC
https://github.com/nodeca/js-yaml/commit/6a8e05f9…	x_refsource_MISC
https://github.com/nodeca/js-yaml/commit/d90b6612…	x_refsource_MISC
https://github.com/nodeca/js-yaml/releases/tag/3.15.2	x_refsource_MISC
https://github.com/nodeca/js-yaml/releases/tag/4.3.2	x_refsource_MISC
https://github.com/nodeca/js-yaml/releases/tag/5.4.1	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
nodeca	js-yaml	Affected: >= 3.0.0, < 3.15.2 Affected: >= 4.0.0, < 4.3.2 Affected: >= 5.0.0, < 5.4.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-84375",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-02T13:43:50.850378Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-02T16:02:06.745Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "js-yaml",
          "vendor": "nodeca",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 3.0.0, \u003c 3.15.2"
            },
            {
              "status": "affected",
              "version": "\u003e= 4.0.0, \u003c 4.3.2"
            },
            {
              "status": "affected",
              "version": "\u003e= 5.0.0, \u003c 5.4.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 until 3.15.2, 4.3.2, and 5.4.1, maxTotalMergeKeys in lib/js-yaml/loader.js and lib/loader.js does not count empty mapping sources while processing the merge key \u003c\u003c. An attacker can alias a large sequence of empty mappings into many merge targets, causing O(N * K) processing while totalMergeKeys remains unchanged and the configured resource limit is never reached. A relatively small YAML document can therefore cause prolonged CPU consumption in applications that parse untrusted YAML, and merge processing is enabled by default on these release lines. In v3 \u0026 v4, merge is enabled by default so the severity score is higher. This issue is fixed in versions 3.15.2, 4.3.2, and 5.4.1."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "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",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-400",
              "description": "CWE-400: Uncontrolled Resource Consumption",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-407",
              "description": "CWE-407: Inefficient Algorithmic Complexity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-28T21:32:39.387Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/nodeca/js-yaml/security/advisories/GHSA-2883-xcg3-v3hh",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/nodeca/js-yaml/security/advisories/GHSA-2883-xcg3-v3hh"
        },
        {
          "name": "https://github.com/nodeca/js-yaml/pull/797",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nodeca/js-yaml/pull/797"
        },
        {
          "name": "https://github.com/nodeca/js-yaml/commit/3485bc06ff8a0251505f44a00414d90df2466639",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nodeca/js-yaml/commit/3485bc06ff8a0251505f44a00414d90df2466639"
        },
        {
          "name": "https://github.com/nodeca/js-yaml/commit/6a8e05f9a485188ed730ac81e81ae221352ef480",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nodeca/js-yaml/commit/6a8e05f9a485188ed730ac81e81ae221352ef480"
        },
        {
          "name": "https://github.com/nodeca/js-yaml/commit/d90b6612a5a84385bdcb556c44578eac76dc0f6b",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nodeca/js-yaml/commit/d90b6612a5a84385bdcb556c44578eac76dc0f6b"
        },
        {
          "name": "https://github.com/nodeca/js-yaml/releases/tag/3.15.2",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nodeca/js-yaml/releases/tag/3.15.2"
        },
        {
          "name": "https://github.com/nodeca/js-yaml/releases/tag/4.3.2",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nodeca/js-yaml/releases/tag/4.3.2"
        },
        {
          "name": "https://github.com/nodeca/js-yaml/releases/tag/5.4.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nodeca/js-yaml/releases/tag/5.4.1"
        }
      ],
      "source": {
        "advisory": "GHSA-2883-xcg3-v3hh",
        "discovery": "UNKNOWN"
      },
      "title": "js-yaml: maxTotalMergeKeys does not limit CPU use for empty merge sources"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-84375",
    "datePublished": "2026-09-01T21:43:13.617Z",
    "dateReserved": "2026-09-01T16:27:58.129Z",
    "dateUpdated": "2026-09-28T21:32:39.387Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
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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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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OESA-2026-4060 (CVE-2026-84375)

CVE-2026-84375 (GCVE-0-2026-84375)

Tags

Sightings

Nomenclature

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