CVE-2025-64718CWE-1321

CVE-2025-64718

Medium · published November 13, 2025

CVSS v3.1
5.3
EPSS
0%
Percentile
35.5
In the wild
Unconfirmed
What it is

js-yaml is a JavaScript YAML parser and dumper. In js-yaml before 4.1.1 and 3.14.2, 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 and 3.14.2. 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).

The record
Technical detail
CVSS v3.1
5.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00423 · 35.5th percentile
Weakness
CWE-1321 · Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Published
2025-11-13T21:15Z
Affected products (2)
ProductVersionsFixed in
nodeca/js-yaml< 3.14.23.14.2
nodeca/js-yaml≥ 4.0.0, < 4.1.14.1.1
References (5)
EPSS history
Timeline
  • 13 NOV 15:32Z
    js-yaml has prototype pollution in merge (<<)
    cvelistv5