{"schema":"threatline.record/2","record":{"id":"CVE-2026-112712","aliases":["GHSA-5p92-8765-9fv8"],"summary":"@fastify/middie vulnerable to path-scoped middleware bypass via scope prefix mismatch","details":"@fastify/middie is the Express-style middleware engine for Fastify. In versions from 9.0.0 through 9.3.5, the use() function joined a path-scoped middleware's mount path to the plugin scope prefix in a way that could diverge from the path Fastify's router serves, most often when the scope prefix ended in a slash, and also for array mount paths and for mount paths written without a leading slash. When the two paths disagreed, the middleware was silently skipped while the route handler still ran, so path-scoped middleware such as authentication, authorization, or rate limiting could be bypassed by a single unauthenticated request. The issue is fixed in @fastify/middie 9.3.6, and users should upgrade to 9.3.6 or later. As a workaround, enforce authorization in a Fastify hook such as preHandler that runs after the router has resolved the request.","categories":["Frameworks"],"product":"@fastify/middie","vendor":"@fastify/middie","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-112712","source_modified_at":"2026-10-20T20:43:48.681Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"@fastify/middie","vendor":"@fastify/middie","versions":[{"versionType":"semver","status":"affected","version":"9.0.0","lessThan":"9.3.6"},{"versionType":"semver","status":"unaffected","version":"9.3.6"}],"defaultStatus":"unaffected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-112712","source_modified_at":"2026-10-20T20:43:48.681Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"@fastify/middie","ecosystem":null},"version":"9.3.6","basis":"first unaffected version stated in the CVE record"}],"cvss":9.1,"severity":"Critical","kev":{"listed":false},"epss":{"probability":0.00314,"percentile":0.23159,"score_date":"2026-10-23"},"published_at":"2026-10-20T20:43:48.681Z","modified_at":"2026-10-20T20:43:48.681Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-112712","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-20T20:43:48.681Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-112712","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/fastify/middie/security/advisories/GHSA-5p92-8765-9fv8"},{"source":"CVE List","url":"https://cna.openjsf.org/security-advisories.html"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-20T20:43:48.681Z","content_hash":"bd38a3ed0b76c239e3b86d5615bb05fc178d8d86d03c74759f0613e5b0bdca34"}}