Vulnerability Analysis
@fastify/static vulnerable to route guard bypass via encoded path separators
CVE-2026-6414
@fastify/static versions 8.0.0 through 9.1.0 decode percent-encoded path separators (%2F) before filesystem resolution, while Fastify's router treats them as literal characters. This mismatch allows attackers to bypass route-based middleware or guards that protect files served by @fastify/static. For example, a route guard on a protected path can be circumvented by encoding the path separator in the URL. Upgrade to @fastify/static 9.1.1 to fix this issue. There are no workarounds.
No Active Exploit Signals
CVSS Base Score
5.9
MEDIUM
Exploitability:2.3
Impact Score:3.6
Temporal Score:-
EPSS:0.40%
Threat Intelligence Signals
CISA KEV
No
KEV Date Added
—
Ransomware Use
—
KEV Due Date
—
VulnCheck In-the-Wild
No
Nuclei Template
No
EPSS Score
0.398%
EPSS Percentile
31.5th pct
GHSA ID
GitHub Severity
MODERATE
SSVC Exploitation
—
SSVC Automatable
—
Vulnerability Class
—
Identity & Timeline
| Status | - |
| Assigning Authority | - |
| Discovered Via | - |
| Record Completeness | - |
| CVSS Version / Source | - |
| Reserved | - |
| Published | - |
| Patch Date (date_public) | - |
| Exploit DB Date | - |
| First GitHub PoC Date | - |
| Last Updated | - |
| Time to Patch (Days to fix) | - |
| Exploit Release Gap | - |
| PoC Release Gap | - |
| Exploit DB References | None identified |
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| No affected products specified. | ||
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