{"id":"CVE-2026-107301","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-107301","generatedAt":"2026-10-28T02:57:33.562Z","title":"msgpack5 is a msgpack v5 implementation for node.js and the browser.","description":"msgpack5 is a msgpack v5 implementation for node.js and the browser. Prior to 6.1.0, constructing msgpack5 with an empty or partial options object disables the default protoAction: 'error' protection. A decoded map containing a __proto__ key can then replace the decoded object's prototype, potentially changing inherited properties or downstream behavior, although Object.prototype is not modified globally. This issue is fixed in version 6.1.0.","published":"2026-10-08T17:17:16.000Z","lastModified":"2026-10-14T01:17:06.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L"},"cwe":["CWE-1321"],"affected":[],"epss":{"score":0.00366,"percentile":0.30226,"date":"2026-10-26","history":[{"date":"2026-10-09","score":0.00366,"percentile":0.28438}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.37%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-08T17:17:16.000Z","detail":{"score":"6.5","severity":"MEDIUM","publishedAt":"2026-10-08T17:17:16.143Z"},"summary":"New CVE, medium severity (CVSS 6.5)."}],"references":[{"url":"https://github.com/mcollina/msgpack5/commit/20e82600ac9462e679c8a45e5723315f21e2c774","source":"security-advisories@github.com"},{"url":"https://github.com/mcollina/msgpack5/releases/tag/v6.1.0","source":"security-advisories@github.com"},{"url":"https://github.com/mcollina/msgpack5/security/advisories/GHSA-8hq7-ggx2-cc6m","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-107301","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}