CVE-2026-59870
Published:July 08, 2026
Updated:August 04, 2026
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.
Affected Packages
https://github.com/nodeca/js-yaml.git (GITHUB):
Affected version(s) >=5.0.0 <5.2.1Fix Suggestion:
Update to version 5.2.1js-yaml (NPM):
Affected version(s) >=5.0.0 <5.2.1Fix Suggestion:
Update to version 5.2.1Related Resources (6)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.9
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Weakness Type (CWE)
EPSS
Base Score:
0.41