CVE-2025-64718
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).
Published:Nov 13, 2025
Last Modified:Feb 2, 2026
EPS:Nov 13, 2025
EPSS Score:0.00021
CVSS Score:5.3
Affected Products
Vendor
Product
Action
Vendor
Js-yaml
Product
Js-yaml
Js-yaml
Js-yaml
Vendor
Nodeca
Product
Js-yaml
Nodeca
Js-yaml
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
References
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
