CVE-2026-6414
MEDIUMDescription
@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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Exploit Intelligence
Low risk: more likely to be exploited than 34% of all known CVEs.
References
Related Vulnerabilities
Other CWE-177 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2022-27780 | High | 7.5 | 2.3% | - | Fix |
| CVE-2018-3718 | Medium | 5.3 | 1.3% | - | Fix |
| CVE-2022-3854 | Medium | 6.5 | 0.6% | - | Fix |
| CVE-2026-41041 | Critical | 9.1 | 0.5% | - | Fix |
| CVE-2026-22031 | High | 8.4 | 0.5% | - | Fix |
| CVE-2026-29045 | High | 7.5 | 0.4% | - | Fix |
Common questions
How do I fix CVE-2026-6414?
Upgrade fastify-static to 9.1.1 or later.
Is CVE-2026-6414 being actively exploited?
Not that we know of. CVE-2026-6414 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.41% is the estimated probability that it will be exploited in the next 30 days. That is higher than 34% of all scored CVEs.
How severe is CVE-2026-6414?
CVE-2026-6414 has a CVSS v3 base score of 5.9, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-6414 affect?
Published advisories record a fix for fastify-static (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-6414
Markdown
[](https://tridentstack.com/cve/CVE-2026-6414)HTML
<a href="https://tridentstack.com/cve/CVE-2026-6414"><img src="https://tridentstack.com/cve/badge/CVE-2026-6414.svg" alt="CVE-2026-6414"></a>Find and fix vulnerabilities across your fleet
TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-23.