CVE-2026-59868

MEDIUM5.3

js-yaml: YAML merge-key chains can force quadratic CPU consumption

Published Jul 8, 2026

Modified 2 weeks ago

Details

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.

References

WEB

https://github.com/nodeca/js-yaml/commit/3105455b81dee69e0fd36e09ac0b2ccfdb54adc1

WEB

https://github.com/nodeca/js-yaml/releases/tag/5.2.0

WEB

https://github.com/nodeca/js-yaml/security/advisories/GHSA-g796-fgmg-93mv

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2026-59868

CVSS Analysis

CVSS v3.1

5.3