honojs hono up to 4.12.11 path traversal

Summaryinfo

A vulnerability was found in honojs hono up to 4.12.11. It has been rated as critical. Impacted is an unknown function. This manipulation causes path traversal. This vulnerability is handled as CVE-2026-39407. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in honojs hono up to 4.12.11 and classified as critical. Affected by this vulnerability is an unknown function. The manipulation with an unknown input leads to a path traversal vulnerability. The CWE definition for the vulnerability is CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. As an impact it is known to affect confidentiality. The summary by CVE is:

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.12, a path handling inconsistency in serveStatic allows protected static files to be accessed by using repeated slashes (//) in the request path. When route-based middleware (e.g., /admin/*) is used for authorization, the router may not match paths containing repeated slashes, while serveStatic resolves them as normalized paths. This can lead to a middleware bypass. This vulnerability is fixed in 4.12.12.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-39407 since 04/07/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1006 according to MITRE ATT&CK.

Upgrading to version 4.12.12 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1407). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• IBM App Connect Enterprise
• Red Hat Enterprise Linux
• Fedora Linux
• IBM QRadar SIEM
• IBM MQ
• IBM Maximo Asset Management
• IBM Sterling Connect:Direct

Productinfo

Vendor

• honojs

Name

• hono

Version

• 4.12.0
• 4.12.1
• 4.12.2
• 4.12.3
• 4.12.4
• 4.12.5
• 4.12.6
• 4.12.7
• 4.12.8
• 4.12.9
• 4.12.10
• 4.12.11

Website

• Product: https://github.com/honojs/hono/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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