CVE-2026-59869: CWE-407: Inefficient Algorithmic Complexity in nodeca js-yaml
js-yaml versions from 3.0.0 before 3.15.0 and from 4.0.0 before 4.3.0 have an inefficient algorithmic complexity issue. Parsing YAML documents with a chain of mappings using merge keys can cause quadratic CPU time consumption, leading to potential denial of service. This vulnerability is fixed in versions 3.15.0 and 4.3.0.
AI Analysis
Technical Summary
The js-yaml JavaScript library suffers from a CWE-407 inefficient algorithmic complexity vulnerability in versions >=3.0.0 <3.15.0 and >=4.0.0 <4.3.0. When parsing YAML documents that contain a chain of mappings using merge keys where each mapping merges the previous one, the CPU time required grows quadratically relative to the document size, which itself grows linearly. This can cause excessive CPU consumption during parsing. The issue is resolved in versions 3.15.0 and 4.3.0.
Potential Impact
This vulnerability can cause high CPU usage leading to denial of service conditions when processing specially crafted YAML documents. There is no impact on confidentiality or integrity, only availability is affected.
Mitigation Recommendations
Upgrade js-yaml to version 3.15.0 or later if using the 3.x branch, or to version 4.3.0 or later if using the 4.x branch. No other mitigations are indicated. Patch status is confirmed fixed in these versions.
CVE-2026-59869: CWE-407: Inefficient Algorithmic Complexity in nodeca js-yaml
Description
js-yaml versions from 3.0.0 before 3.15.0 and from 4.0.0 before 4.3.0 have an inefficient algorithmic complexity issue. Parsing YAML documents with a chain of mappings using merge keys can cause quadratic CPU time consumption, leading to potential denial of service. This vulnerability is fixed in versions 3.15.0 and 4.3.0.
CVSS v3.1
Score 7.5high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The js-yaml JavaScript library suffers from a CWE-407 inefficient algorithmic complexity vulnerability in versions >=3.0.0 <3.15.0 and >=4.0.0 <4.3.0. When parsing YAML documents that contain a chain of mappings using merge keys where each mapping merges the previous one, the CPU time required grows quadratically relative to the document size, which itself grows linearly. This can cause excessive CPU consumption during parsing. The issue is resolved in versions 3.15.0 and 4.3.0.
Potential Impact
This vulnerability can cause high CPU usage leading to denial of service conditions when processing specially crafted YAML documents. There is no impact on confidentiality or integrity, only availability is affected.
Mitigation Recommendations
Upgrade js-yaml to version 3.15.0 or later if using the 3.x branch, or to version 4.3.0 or later if using the 4.x branch. No other mitigations are indicated. Patch status is confirmed fixed in these versions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-07-07T15:41:53.607Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4e73c2c9d9e3dbe36042b4
Added to database: 07/08/2026, 15:58:58 UTC
Last enriched: 07/08/2026, 16:13:33 UTC
Last updated: 07/08/2026, 21:52:54 UTC
Views: 15
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