{"schema_version":"1.7.3","id":"GHSA-mh29-5h37-fv8m","published":"2025-11-14T14:29:48Z","modified":"2026-07-08T07:59:25.678676685Z","aliases":["CVE-2025-64718"],"related":["CGA-mfcv-6pv8-6v39"],"summary":"js-yaml has prototype pollution in merge (<<)","details":"### Impact\n\nIn js-yaml 4.1.0, 4.0.0, and 3.14.1 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.\n\n### Patches\n\nProblem is patched in js-yaml 4.1.1 and 3.14.2.\n\n### Workarounds\n\nYou 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).\n\n### References\n\nhttps://cheatsheetseries.owasp.org/cheatsheets/Prototype_Pollution_Prevention_Cheat_Sheet.html","affected":[{"package":{"name":"js-yaml","ecosystem":"npm","purl":"pkg:npm/js-yaml"},"ranges":[{"type":"SEMVER","events":[{"introduced":"4.0.0"},{"fixed":"4.1.1"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/11/GHSA-mh29-5h37-fv8m/GHSA-mh29-5h37-fv8m.json"}},{"package":{"name":"js-yaml","ecosystem":"npm","purl":"pkg:npm/js-yaml"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.14.2"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/11/GHSA-mh29-5h37-fv8m/GHSA-mh29-5h37-fv8m.json"}}],"references":[{"type":"WEB","url":"https://github.com/nodeca/js-yaml/security/advisories/GHSA-mh29-5h37-fv8m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-64718"},{"type":"WEB","url":"https://github.com/nodeca/js-yaml/issues/730#issuecomment-3549635876"},{"type":"WEB","url":"https://github.com/nodeca/js-yaml/commit/383665ff4248ec2192d1274e934462bb30426879"},{"type":"WEB","url":"https://github.com/nodeca/js-yaml/commit/5278870a17454fe8621dbd8c445c412529525266"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-mh29-5h37-fv8m"},{"type":"PACKAGE","url":"https://github.com/nodeca/js-yaml"}],"database_specific":{"cwe_ids":["CWE-1321"],"github_reviewed":true,"github_reviewed_at":"2025-11-14T14:29:48Z","nvd_published_at":"2025-11-13T16:15:57Z","severity":"MODERATE"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"}]}