CVE-2026-59870

js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 before 5.2.1, YAML11_SCHEMA support for the !!omap tag in src/tag/sequence/omap.ts uses omapTag.addItem() to perform a linear duplicate-key scan on every insertion, causing O(n^2) CPU consumption when yaml.load() parses a crafted ordered-map document. This issue is fixed in version 5.2.1.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/nodeca/js-yaml/commit/39f3211a2f01b3c6982710cf21434ab7060acefe	Patch
https://github.com/nodeca/js-yaml/releases/tag/5.2.1	Release Notes
https://github.com/nodeca/js-yaml/security/advisories/GHSA-724g-mxrg-4qvm	Exploit Vendor Advisory
https://github.com/nodeca/js-yaml/security/advisories/GHSA-724g-mxrg-4qvm	Exploit Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:nodeca:js-yaml:*:*:*:*:*:node.js:*:*

History

No history.

Information

Published : 2026-07-08 16:16

Updated : 2026-07-10 19:20

NVD link : CVE-2026-59870

Mitre link : CVE-2026-59870

CVE.ORG link : CVE-2026-59870

JSON object : View

Products Affected

nodeca

js-yaml

CWE

CWE-407

Inefficient Algorithmic Complexity

CWE-770

Allocation of Resources Without Limits or Throttling

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