nodeca js-yaml up to 3.14.x/4.2.x JavaScript YAML Parser resource consumption

Summaryinfo

A vulnerability was found in nodeca js-yaml up to 3.14.x/4.2.x. It has been classified as problematic. This impacts an unknown function of the component JavaScript YAML Parser. The manipulation leads to resource consumption. This vulnerability is listed as CVE-2026-59869. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in nodeca js-yaml up to 3.14.x/4.2.x. This issue affects an unknown code block of the component JavaScript YAML Parser. The manipulation with an unknown input leads to a resource consumption vulnerability. Using CWE to declare the problem leads to CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. Impacted is availability. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-59869 since 07/07/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 3.15.0 or 4.3.0 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• nodeca

Name

• js-yaml

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.5
• 3.6
• 3.7
• 3.8
• 3.9
• 3.10
• 3.11
• 3.12
• 3.13
• 3.14
• 4.0
• 4.1
• 4.2

Website

• Product: https://github.com/nodeca/js-yaml/

CPE 2.3info

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CPE 2.2info

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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