{"id":"CVE-2026-6270","summary":"@fastify/middie vulnerable to middleware authentication bypass in child plugin scopes","details":"@fastify/middie versions 9.3.1 and earlier do not register inherited middleware directly on child plugin engine instances. When a Fastify application registers authentication middleware in a parent scope and then registers child plugins with @fastify/middie, the child scope does not inherit the parent middleware. This allows unauthenticated requests to reach routes defined in child plugin scopes, bypassing authentication and authorization checks. Upgrade to @fastify/middie 9.3.2 to fix this issue. There are no workarounds.","aliases":["GHSA-72c6-fx6q-fr5w"],"modified":"2026-07-08T08:14:42.262687365Z","published":"2026-04-16T13:44:46.322Z","related":["GHSA-72c6-fx6q-fr5w","GHSA-hrwm-hgmj-7p9c"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6270.json","cna_assigner":"openjs","cwe_ids":["CWE-436"]},"references":[{"type":"ADVISORY","url":"https://cna.openjsf.org/security-advisories.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6270.json"},{"type":"ADVISORY","url":"https://github.com/fastify/fastify-express/security/advisories/GHSA-hrwm-hgmj-7p9c"},{"type":"ADVISORY","url":"https://github.com/fastify/middie/security/advisories/GHSA-72c6-fx6q-fr5w"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6270"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/fastify/middie","events":[{"introduced":"0"},{"fixed":"792d2f46ae68516d3122c9a4468a5748a34efb47"}],"database_specific":{"source":["AFFECTED_FIELD","CPE_RANGE"],"cpe":"cpe:2.3:a:fastify:fastify\\/middie:*:*:*:*:*:node.js:*:*","extracted_events":[{"introduced":"0"},{"fixed":"9.3.2"}]}}],"versions":["v9.3.1","v9.3.0","v9.2.0","v9.1.0","v9.0.3","v9.0.2","v9.0.1","v8.3.1","v9.0.0","v8.3.0","v8.2.0","v8.1.0","v8.0.0","v7.0.0","v6.0.0","v5.4.0","v5.3.0","v5.2.0","v5.1.0","v5.0.0","v4.1.0","v4.0.1","v3.2.1","v3.2.0","v4.0.0","v3.1.0","v3.0.0","v2.1.1","v2.1.0","v2.0.0","v1.1.0","v1.0.0","v0.3.0","v0.2.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6270.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"}]}