{"id":"GHSA-8hq7-ggx2-cc6m","revision":"4c6588c005624dffb915e2b971a872cf","records":[{"revision":"4c6588c005624dffb915e2b971a872cf","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-8hq7-ggx2-cc6m","aliases":["CVE-2026-107301"],"title":"msgpack5: Partial options disable prototype protection","description":"### Impact\n\nPassing an empty or partial options object disables the default `protoAction: 'error'` protection. A map containing a `__proto__` key can then replace the prototype of the decoded object, potentially changing inherited properties or causing unexpected behavior in downstream code.\n\nOnly the decoded object's prototype is affected; this does not modify `Object.prototype` globally.\n\n### Patches\n\nOptions are now merged with secure defaults without modifying the caller's object. Unsupported `protoAction` values are rejected.\n\n### Workarounds\n\nExplicitly set `protoAction: 'error'` whenever constructing a msgpack5 instance, and validate decoded values before use.","state":0,"publishedAt":"2026-10-08T17:39:57+00:00","modifiedAt":"2026-10-08T18:00:08.8992869+00:00","affected":[{"ecosystem":"npm","name":"msgpack5","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"6.1.0"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://github.com/mcollina/msgpack5/security/advisories/GHSA-8hq7-ggx2-cc6m","https://github.com/mcollina/msgpack5/commit/20e82600ac9462e679c8a45e5723315f21e2c774","https://github.com/mcollina/msgpack5","https://github.com/mcollina/msgpack5/releases/tag/v6.1.0"],"sourceUrl":"https://github.com/advisories/GHSA-8hq7-ggx2-cc6m","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-8hq7-ggx2-cc6m","identifiers":["GHSA-8hq7-ggx2-cc6m","CVE-2026-107301"]},"retained":false,"historicalAffected":[]}],"coverage":[]}