Vulnerability Description
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).
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Nodeca | Js-Yaml | < 3.14.2 |
Related Weaknesses (CWE)
References
- https://github.com/nodeca/js-yaml/commit/383665ff4248ec2192d1274e934462bb3042687Patch
- https://github.com/nodeca/js-yaml/commit/5278870a17454fe8621dbd8c445c41252952526Patch
- https://github.com/nodeca/js-yaml/issues/730#issuecomment-3549635876Issue Tracking
- https://github.com/nodeca/js-yaml/security/advisories/GHSA-mh29-5h37-fv8mVendor Advisory
- https://github.com/advisories/GHSA-mh29-5h37-fv8mVendor Advisory
FAQ
What is CVE-2025-64718?
CVE-2025-64718 is a vulnerability with a CVSS score of 5.3 (MEDIUM). 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 pollutio...
How severe is CVE-2025-64718?
CVE-2025-64718 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-64718?
Check the references section above for vendor advisories and patch information. Affected products include: Nodeca Js-Yaml.