HIGHCVE-2026-2880Published Modified CNA openjs
CVE-2026-2880: @fastify/middie has an improper path normalization vulnerability
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.
Metrics
- CVSS v4.0
- 8.2
- Severity
- HIGH
- Fixed in
- 9.2.0
- Affected Products
- 1
Fix available
9.2.0
Affected packages
- @fastify/middie / @fastify/middie< 9.2.0 (from 0.0.0)
CVSS Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:NReferences