Resource exhaustion in js-yaml (npm) - #VU136866
Published: July 3, 2026
Vulnerability identifier: #VU136866
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: N/A
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: npm Inc.
Affected software:
js-yaml (npm)
js-yaml (npm)
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to uncontrolled resource consumption in the js-yaml parser when parsing YAML documents with merge keys enabled. A remote attacker can send a specially crafted YAML document containing a chain of merged mappings to cause a denial of service.
The issue occurs only when merge keys are enabled.
Remediation
Install security update from vendor's website.