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CVE-2026-2880GHSA-8P85-9QPW-FWGW

@fastify/middie has an improper path normalization vulnerability

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 9.2.0
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: partial

Summary

A vulnerability in @fastify/middie versions < 9.2.0 can result in authentication/authorization bypass when using path-scoped middleware (for example, app.use('/secret', auth)). When Fastify router normalization options are enabled (such as ignoreDuplicateSlashes, useSemicolonDelimiter, and related trailing-slash behavior), crafted request paths may bypass middleware checks while still being routed to protected handlers.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: partial

  3. Record last updated

Affected versions

  • @fastify/middie @fastify/middie

    From 0.0.0 · fixed in 9.2.0

  • @fastify/middienpm

    fixed in 9.2.0

References 1

GitHub · fastify/middie