CVE-2026-59869 Details
Description
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.
A vulnerability in js-yaml, a JavaScript YAML parser and dumper, allows for quadratic CPU time consumption when parsing documents that exploit a specific use of merge keys. This issue affects js-yaml versions 3.0.0 prior to 3.15.0 and 4.0.0 prior to 4.3.0. The vulnerability is triggered by a chain of mappings where each mapping merges the previous one, leading to excessive processing time for documents of certain sizes.
Users can update to js-yaml versions 3.15.0 or 4.3.0, both of which include the necessary fix.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jul 9, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-407 | Inefficient Algorithmic Complexity | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| nodeca js-yaml | >= 3.0.0, < 3.15.0 >= 4.0.0, < 4.3.0 |
CPE
Remediation
| |
Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 13, 2026 | Initial Analysis | [email protected] |
| Jul 9, 2026 | CVE Modified | CISA-ADP |
| Jul 8, 2026 | New CVE Received | [email protected] |