CVE-2026-59868: CWE-407: Inefficient Algorithmic Complexity in nodeca js-yaml
js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 before 5.2.0, when merge keys are enabled, 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 version 5.2.0.
AI Analysis
Technical Summary
The js-yaml JavaScript library versions >=5.0.0 and <5.2.0 exhibit a CWE-407 inefficient algorithmic complexity vulnerability when merge keys are enabled. Specifically, parsing a YAML document with a chain of mappings that merge the previous mapping causes the CPU time to grow quadratically relative to the document size, which itself grows linearly. This inefficiency can lead to excessive CPU consumption during parsing. The vulnerability is resolved in version 5.2.0.
Potential Impact
This vulnerability can cause denial of service conditions by consuming excessive CPU resources during YAML parsing, potentially impacting availability of applications using affected js-yaml versions. There is no impact on confidentiality or integrity. No known exploits are reported in the wild.
Mitigation Recommendations
Upgrade js-yaml to version 5.2.0 or later, where this inefficient algorithmic complexity issue is fixed. Patch status is confirmed by the version range and fix version stated in the description. No other mitigation is indicated.
CVE-2026-59868: CWE-407: Inefficient Algorithmic Complexity in nodeca js-yaml
Description
js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 before 5.2.0, when merge keys are enabled, 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 version 5.2.0.
CVSS v3.1
Score 5.3medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The js-yaml JavaScript library versions >=5.0.0 and <5.2.0 exhibit a CWE-407 inefficient algorithmic complexity vulnerability when merge keys are enabled. Specifically, parsing a YAML document with a chain of mappings that merge the previous mapping causes the CPU time to grow quadratically relative to the document size, which itself grows linearly. This inefficiency can lead to excessive CPU consumption during parsing. The vulnerability is resolved in version 5.2.0.
Potential Impact
This vulnerability can cause denial of service conditions by consuming excessive CPU resources during YAML parsing, potentially impacting availability of applications using affected js-yaml versions. There is no impact on confidentiality or integrity. No known exploits are reported in the wild.
Mitigation Recommendations
Upgrade js-yaml to version 5.2.0 or later, where this inefficient algorithmic complexity issue is fixed. Patch status is confirmed by the version range and fix version stated in the description. No other mitigation is indicated.
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: 6a4e73c2c9d9e3dbe36042af
Added to database: 07/08/2026, 15:58:58 UTC
Last enriched: 07/16/2026, 10:14:03 UTC
Last updated: 08/22/2026, 14:29:37 UTC
Views: 59
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