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

Vulnerability from cvelistv5 – Published: 2026-09-01 21:43 – Updated: 2026-09-28 21:32
VLAI
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 CNA under the mitre root
CNA scorecard C 72/100 over 7634 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
nodeca js-yaml Affected: >= 3.0.0, < 3.15.2
Affected: >= 4.0.0, < 4.3.2
Affected: >= 5.0.0, < 5.4.1
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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}



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