CVE-2026-6414
@fastify/static vulnerable to route guard bypass via encoded path separators
Description
@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.
INFO
Published Date :
April 16, 2026, 1:16 p.m.
Last Modified :
April 23, 2026, 7:41 p.m.
Remotely Exploit :
Yes !
Source :
ce714d77-add3-4f53-aff5-83d477b104bb
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | ce714d77-add3-4f53-aff5-83d477b104bb |
Solution
- Upgrade @fastify/static to version 9.1.1.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-6414.
| URL | Resource |
|---|---|
| https://cna.openjsf.org/security-advisories.html | Third Party Advisory |
| https://github.com/fastify/fastify-static/security/advisories/GHSA-x428-ghpx-8j92 | Vendor Advisory |
| https://github.com/fastify/middie/security/advisories/GHSA-cxrg-g7r8-w69p | Not Applicable |
| https://github.com/honojs/hono/security/advisories/GHSA-q5qw-h33p-qvwr | Not Applicable |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-6414 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-6414
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-6414 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-6414 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 23, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:fastify:fastify-static:*:*:*:*:*:*:*:* versions from (including) 8.0.0 up to (excluding) 9.1.1 Added Reference Type openjs: https://cna.openjsf.org/security-advisories.html Types: Third Party Advisory Added Reference Type openjs: https://github.com/fastify/fastify-static/security/advisories/GHSA-x428-ghpx-8j92 Types: Vendor Advisory Added Reference Type openjs: https://github.com/fastify/middie/security/advisories/GHSA-cxrg-g7r8-w69p Types: Not Applicable Added Reference Type openjs: https://github.com/honojs/hono/security/advisories/GHSA-q5qw-h33p-qvwr Types: Not Applicable -
New CVE Received by ce714d77-add3-4f53-aff5-83d477b104bb
Apr. 16, 2026
Action Type Old Value New Value Added Description @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. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-177 Added Reference https://cna.openjsf.org/security-advisories.html Added Reference https://github.com/fastify/fastify-static/security/advisories/GHSA-x428-ghpx-8j92 Added Reference https://github.com/fastify/middie/security/advisories/GHSA-cxrg-g7r8-w69p Added Reference https://github.com/honojs/hono/security/advisories/GHSA-q5qw-h33p-qvwr