CVE-2026-84375 (GCVE-0-2026-84375)
Vulnerability from cvelistv5
Published
2026-09-01 21:43
Modified
2026-09-28 21:32
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-400 - Uncontrolled Resource Consumption
  • CWE-407 - Inefficient Algorithmic Complexity
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.
References
Impacted products
Vendor Product Version
nodeca js-yaml Version: >= 3.0.0, < 3.15.2
Version: >= 4.0.0, < 4.3.2
Version: >= 5.0.0, < 5.4.1
 Create a notification for this product.
Show details on NVD website

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",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-84375\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-09-02T13:43:50.850378Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-09-02T13:43:51.973Z\"}}], \"cna\": {\"title\": \"js-yaml: maxTotalMergeKeys does not limit CPU use for empty merge sources\", \"source\": {\"advisory\": \"GHSA-2883-xcg3-v3hh\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}], \"affected\": [{\"vendor\": \"nodeca\", \"product\": \"js-yaml\", \"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\"}]}], \"references\": [{\"url\": \"https://github.com/nodeca/js-yaml/security/advisories/GHSA-2883-xcg3-v3hh\", \"name\": \"https://github.com/nodeca/js-yaml/security/advisories/GHSA-2883-xcg3-v3hh\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/nodeca/js-yaml/pull/797\", \"name\": \"https://github.com/nodeca/js-yaml/pull/797\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/nodeca/js-yaml/commit/3485bc06ff8a0251505f44a00414d90df2466639\", \"name\": \"https://github.com/nodeca/js-yaml/commit/3485bc06ff8a0251505f44a00414d90df2466639\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/nodeca/js-yaml/commit/6a8e05f9a485188ed730ac81e81ae221352ef480\", \"name\": \"https://github.com/nodeca/js-yaml/commit/6a8e05f9a485188ed730ac81e81ae221352ef480\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/nodeca/js-yaml/commit/d90b6612a5a84385bdcb556c44578eac76dc0f6b\", \"name\": \"https://github.com/nodeca/js-yaml/commit/d90b6612a5a84385bdcb556c44578eac76dc0f6b\", \"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/3.15.2\", \"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/4.3.2\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/nodeca/js-yaml/releases/tag/5.4.1\", \"name\": \"https://github.com/nodeca/js-yaml/releases/tag/5.4.1\", \"tags\": [\"x_refsource_MISC\"]}], \"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.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-400\", \"description\": \"CWE-400: Uncontrolled Resource Consumption\"}]}, {\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-407\", \"description\": \"CWE-407: Inefficient Algorithmic Complexity\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-09-28T21:32:39.387Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-84375\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-09-28T21:32:39.387Z\", \"dateReserved\": \"2026-09-01T16:27:58.129Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-09-01T21:43:13.617Z\", \"assignerShortName\": \"GitHub_M\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.