CVE-2025-64718

Updated on 13 Nov 2025

Severity

5.3 Medium severity

Details

CVSS score
5.3
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Overview

About vulnerability

js-yaml is a JavaScript YAML parser and dumper. In js-yaml 4.1.0 and below, it’s possible for an attacker to modify the prototype of the result of a parsed yaml document via prototype pollution (__proto__). All users who parse untrusted yaml documents may be impacted. The problem is patched in js-yaml 4.1.1. Users can protect against this kind of attack on the server by using node --disable-proto=delete or deno (in Deno, pollution protection is on by default).

Details

Affected packages:
icu @ 67.1 (+4 more)
js-yaml is a JavaScript YAML parser and dumper. In js-yaml 4.1.0 and below, it’s possible for an attacker to modify the prototype of the result of a parsed yaml document via prototype pollution (__proto__). All users who parse untrusted yaml documents may be impacted. The problem is patched in js-yaml 4.1.1. Users can protect against this kind of attack on the server by using node --disable-proto=delete or deno (in Deno, pollution protection is on by default).

Fixes