CVE-2026-84375

Name of the Vulnerable Software and Affected Versions js-yaml versions 3.0.0 through 3.15.1 js-yaml versions prior to 4.3.2

Description An issue exists where maxTotalMergeKeys in lib/js-yaml/loader.js and lib/loader.js fails to count empty mapping sources when processing the merge key <<. This allows an attacker to alias a large sequence of empty mappings into numerous merge targets, resulting in O(N * K) processing time. Because the resource limit remains unchanged, a small YAML document can lead to prolonged CPU consumption in applications that parse untrusted YAML, as merge processing is enabled by default.

Recommendations Update js-yaml to version 3.15.2. Update js-yaml to version 4.3.2.