CVE-2026-6414

MEDIUM EPSS 31.6%
Published Apr 16, 20262mo ago · Modified Jun 17, 20261w ago
5.9 CVSS 3.1
Medium
Find Similar
Published Apr 16, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score
5.9
Exploitability
2.2
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity None
Availability None

Threat Intelligence

EPSS Exploit Probability
31.6% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-177

Affected Products 1

VendorProductVersionRange
fastifyfastify-static*≥8.0.0  –  <9.1.1

References 4

  • cna.openjsf.org https://cna.openjsf.org/security-advisories.html
    Third Party Advisory
  • github.com https://github.com/fastify/fastify-static/security/advisories/GHSA-x428-ghpx-8j92
    Vendor Advisory
  • github.com https://github.com/fastify/middie/security/advisories/GHSA-cxrg-g7r8-w69p
    Not Applicable
  • github.com https://github.com/honojs/hono/security/advisories/GHSA-q5qw-h33p-qvwr
    Not Applicable

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.