CVE-2026-84375 (High) detected in js-yaml-4.1.0.tgz, js-yaml-3.14.1.tgz

[mend-bolt-for-github]

CVE-2026-84375 - High Severity Vulnerability

Vulnerable Libraries - js-yaml-4.1.0.tgz, js-yaml-3.14.1.tgz

js-yaml-4.1.0.tgz

YAML 1.2 parser and serializer

Library home page: https://registry.npmjs.org/js-yaml/-/js-yaml-4.1.0.tgz

Sample Path to Dependency File: /package.json

Path to vulnerable library: /node_modules/eslint/node_modules/js-yaml/package.json,/node_modules/@⁠eslint/eslintrc/node_modules/js-yaml/package.json

Dependency Hierarchy:

• eslint-8.3.0.tgz (Root Library)
  • ❌ js-yaml-4.1.0.tgz (Vulnerable Library)

js-yaml-3.14.1.tgz

YAML 1.2 parser and serializer

Library home page: https://registry.npmjs.org/js-yaml/-/js-yaml-3.14.1.tgz

Sample Path to Dependency File: /package.json

Path to vulnerable library: /node_modules/js-yaml/package.json

Dependency Hierarchy:

• build-angular-13.0.3.tgz (Root Library)
  • babel-plugin-istanbul-6.1.1.tgz
    • load-nyc-config-1.1.0.tgz
      • ❌ js-yaml-3.14.1.tgz (Vulnerable Library)

Found in HEAD commit: 977ea6ccaaf2045985ee40cacd5f6d676fa1a047

Found in base branch: master

Vulnerability Details

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.

Publish Date: 2026-09-01

URL: CVE-2026-84375

CVSS 3 Score Details (7.5)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: None
  • Integrity Impact: None
  • Availability Impact: High

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Origin: GHSA-2883-xcg3-v3hh

Release Date: 2026-09-01

Fix Resolution (js-yaml): 4.3.2

Direct dependency fix Resolution (eslint): 10.0.0

Fix Resolution (js-yaml): 4.3.2

Direct dependency fix Resolution (@⁠angular-devkit/build-angular): 13.0.4

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