CVE-2026-84375

A flaw was found in js-yaml, a JavaScript YAML parser. An attacker can exploit this by providing a specially crafted YAML document that causes the parser to perform excessive processing when handling merge keys with empty sources. This can lead to prolonged CPU consumption, effectively causing a denial of service (DoS) for applications that process untrusted YAML input.

This is an Important denial of service vulnerability in js-yaml, affecting applications that process untrusted YAML input. The flaw allows an attacker to craft a small YAML document that, when parsed, can lead to prolonged CPU consumption due to inefficient merge key processing, potentially exhausting system resources. This is particularly relevant where applications handle external YAML data and have merge processing enabled by default.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.