CVE-2026-59869
Published:July 08, 2026
Updated:July 30, 2026
js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 before 3.15.0 and from 4.0.0 before 4.3.0, js-yaml can spend quadratic CPU time parsing a document whose size grows only linearly when a chain of mappings uses merge keys where each mapping merges the previous one. This issue is fixed in versions 3.15.0 and 4.3.0.
Affected Packages
js-yaml (CDN_JS):
Affected version(s) >=3.0.2 <3.15.0Fix Suggestion:
Update to version 3.15.0js-yaml (CDN_JS):
Affected version(s) >=4.0.0 <4.3.0Fix Suggestion:
Update to version 4.3.0https://github.com/nodeca/js-yaml.git (GITHUB):
Affected version(s) >=3.0.0 <3.15.0Fix Suggestion:
Update to version 3.15.0https://github.com/nodeca/js-yaml.git (GITHUB):
Affected version(s) >=4.0.0 <4.3.0Fix Suggestion:
Update to version 4.3.0js-yaml (NPM):
Affected version(s) >=3.0.0 <3.15.0Fix Suggestion:
Update to version 3.15.0js-yaml (NPM):
Affected version(s) >=4.0.0 <4.3.0Fix Suggestion:
Update to version 4.3.0Related Resources (8)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
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
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
EPSS
Base Score:
0.42