CVE-2026-59868 MEDIUM

CVE-2026-59868: js-yaml: YAML merge-key chains can force quadratic CPU consumption

Vendor Nodeca
Product js-yaml
Weakness CWE-407
Published July 8, 2026
Last update July 8, 2026
View on NVD All CVEs

CVSS base score

5.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

July 8, 2026 CVE published