SB20260919189 - Inefficient Algorithmic Complexity in js-yaml (npm)
Published: September 19, 2026
Security Bulletin ID
SB20260919189
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Inefficient Algorithmic Complexity (CVE-ID: CVE-2026-84375)
CWE-ID: CWE-407 - Inefficient Algorithmic Complexity
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to inefficient algorithmic complexity in the js-yaml YAML loader when processing a crafted YAML document containing repeated merges of empty mappings. A remote attacker can submit a crafted YAML document to cause a denial of service.
In versions 3 and 4, merge support is enabled by default.
Remediation
Install update from vendor's website.