CVE-2026-59868

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.

PUBLISHED Reserved 2026-07-07 | Published 2026-07-08 | Updated 2026-07-09 | Assigner GitHub_M

Problem types

CWE-407: Inefficient Algorithmic Complexity

Product status

References

github.com/...s-yaml/security/advisories/GHSA-g796-fgmg-93mv exploit

github.com/...s-yaml/security/advisories/GHSA-g796-fgmg-93mv

github.com/...ommit/3105455b81dee69e0fd36e09ac0b2ccfdb54adc1

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

cve.org (CVE-2026-59868)

nvd.nist.gov (CVE-2026-59868)

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