CVE-2026-29045
Inconsistent URL Decoding in Hono serveStatic Enables Unauthorized Access
Publication date: 2026-03-04
Last updated on: 2026-03-06
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| hono | hono | to 4.12.4 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-177 | The product does not properly handle when all or part of an input has been URL encoded. |
Attack-Flow Graph
AI Powered Q&A
How can this vulnerability impact me? :
This vulnerability can lead to unauthorized access to protected static resources within a web application using the Hono framework. Attackers can exploit the inconsistent URL decoding to bypass security controls and access sensitive files or data that should be restricted.
The CVSS score of 7.5 indicates a high severity impact, with the vulnerability being remotely exploitable without any privileges or user interaction, and it can result in high confidentiality impact.
Can you explain this vulnerability to me?
This vulnerability exists in the Hono web application framework prior to version 4.12.4. It occurs because of inconsistent URL decoding between two components: the router and the serveStatic middleware. The router uses decodeURI while serveStatic uses decodeURIComponent. This mismatch allows attackers to use encoded slashes (%2F) in URLs to bypass route-based middleware protections that are meant to restrict access to certain static resources.
As a result, protected static resources can be accessed without proper authorization, even though middleware protections are in place.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, upgrade the Hono framework to version 4.12.4 or later, where the issue has been patched.