mediumCVSS 5.9Vulnerability
CVE-2026-6414
### Impact `@fastify/static` v9.1.0 and earlier decodes percent-encoded path separators (`%2F`) before filesystem resolution, but Fastify's router treats them as literal characters. This creates a routing mismatch: route guards on `/admin/*` do not match `/admin%2Fsecret.html`, but @fastify/static decodes it to `/admin/secret.html` and serves the file. Applications that rely on route-based middleware or guards to protect files served by @fastify/static can be bypassed with encoded path separators. ### Patches Upgrade to `@fastify/static` >= 9.1.1. ### Workarounds None. Upgrade to the patched version.
Properties
- severity
- medium
- summary
- @fastify/static vulnerable to route guard bypass via encoded path separators
- epss_score
- 0.00413
- cvss_score
- 5.9
- ghsa_published
- 2026-04-16T22:34:03Z
- source_url
- https://github.com/advisories/GHSA-x428-ghpx-8j92
- ghsa_updated
- 2026-04-16T22:34:03Z
- ghsa_id
- GHSA-x428-ghpx-8j92
- cve_id
- CVE-2026-6414
- cvss_vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- is_ghsa_only
- false
- epss_percentile
- 0.34376
Related Entities (5)
ENRICHED_BY (1)
→[Source]FIRST EPSS
REPORTED_BY (1)
→[Source]GitHub Advisory Database
VULNERABLE_TO (1)
←[Software]npm/@fastify/static
AFFECTS (1)
→[Software]npm/@fastify/static
HAS_WEAKNESS (1)
→[Weakness]Improper Handling of URL Encoding (Hex Encoding)
Explore deeper with Ninja Signal's threat intelligence graph