CVE-2026-2880
CRITICAL WAF: Medium
CVSS 9.1
Published: 2026-02-27
CWE-20
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.
WAF Coverage Analysis
Improper Input Validation
Medium WAF Coverage
OWASP: A03:2021 Injection
920xxx - Protocol Enforcement 941xxx - XSS / XXE 942xxx - SQL Injection
Affected Software
| Vendor | Product | Version |
|---|---|---|
| openjsf | \@fastify\/middie | up to 9.2.0 |
References
- github.com (Mitigation, Vendor Advisory)