{"schema":"threatline.record/2","record":{"id":"CVE-2026-107301","aliases":["GHSA-8hq7-ggx2-cc6m"],"summary":"msgpack5: Partial options disable prototype protection","details":"### 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.","categories":["Libraries & packages"],"product":"msgpack5","vendor":"mcollina","ecosystem":"npm","affected_ranges":[{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-8hq7-ggx2-cc6m","source_modified_at":"2026-10-08T17:39:58Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"msgpack5"},"range":"< 6.1.0"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-107301","source_modified_at":"2026-10-14T01:02:53.277Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"msgpack5","vendor":"mcollina","versions":[{"version":"< 6.1.0","status":"affected"}],"defaultStatus":null},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-8hq7-ggx2-cc6m","source_modified_at":"2026-10-08T18:00:08.899286917Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"msgpack5","purl":"pkg:npm/msgpack5"},"ranges":[{"events":[{"introduced":"0"},{"fixed":"6.1.0"}],"type":"SEMVER"}],"versions":[]}],"fixed_versions":[{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-8hq7-ggx2-cc6m","source_modified_at":"2026-10-08T17:39:58Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"msgpack5"},"version":"6.1.0"},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-8hq7-ggx2-cc6m","source_modified_at":"2026-10-08T18:00:08.899286917Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"msgpack5","purl":"pkg:npm/msgpack5"},"version":"6.1.0"}],"cvss":6.5,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00366,"percentile":0.29306,"score_date":"2026-10-23"},"published_at":"2026-10-08T17:13:00.613Z","modified_at":"2026-10-14T01:02:53.277Z","provenance":[{"source":"GitHub Advisory Database","url":"https://github.com/advisories/GHSA-8hq7-ggx2-cc6m","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-08T17:39:58Z"},{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-107301","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-14T01:02:53.277Z"},{"source":"OSV","url":"https://osv.dev/vulnerability/GHSA-8hq7-ggx2-cc6m","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-08T18:00:08.899286917Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-107301","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["GitHub Advisory Database","CVE List","OSV","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/mcollina/msgpack5/security/advisories/GHSA-8hq7-ggx2-cc6m","tags":["x_refsource_CONFIRM"]},{"source":"CVE List","url":"https://github.com/mcollina/msgpack5/commit/20e82600ac9462e679c8a45e5723315f21e2c774","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/mcollina/msgpack5/releases/tag/v6.1.0","tags":["x_refsource_MISC"]},{"url":"https://github.com/advisories/GHSA-8hq7-ggx2-cc6m","source":"GitHub Advisory Database"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","ssvc":{"exploitation":"none","automatable":"no","technical_impact":"partial","assessed_at":"2026-10-14T01:02:40.915617Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"ecosystem","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-14T01:02:53.277Z","content_hash":"3b2ee8b80090ade412eed0fe7d97b98ae5270af9dfe0ad886f59cee6154e48c2"}}