GHSA-wmmm-f939-6g9c

Suggest an improvement
Source
https://github.com/advisories/GHSA-wmmm-f939-6g9c
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-wmmm-f939-6g9c/GHSA-wmmm-f939-6g9c.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-wmmm-f939-6g9c
Aliases
  • CVE-2026-39407
Downstream
Related
Published
2026-04-08T00:16:45Z
Modified
2026-04-09T00:59:14.138177898Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N CVSS Calculator
Summary
Hono: Middleware bypass via repeated slashes in serveStatic
Details

Summary

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.

Details

The routing layer and serveStatic handle repeated slashes differently.

For example:

/admin/secret.txt => matches /admin/*
/admin//secret.txt => may not match /admin/*

However, serveStatic may interpret both paths as the same file location (e.g., admin/secret.txt) and return the file.

This inconsistency allows a request such as:

GET //admin/secret.txt

to bypass middleware registered on /admin/* and access protected files.

The issue has been fixed by rejecting paths that contain repeated slashes, ensuring consistent behavior between route matching and static file resolution.

Impact

An attacker can access static files that are intended to be protected by route-based middleware by using repeated slashes in the request path.

This can lead to unauthorized access to sensitive files under the static root.

This issue affects applications that rely on serveStatic together with route-based middleware for access control.

Database specific 
{
    "severity": "MODERATE",
    "github_reviewed": true,
    "nvd_published_at": "2026-04-08T15:16:14Z",
    "cwe_ids": [
        "CWE-22"
    ],
    "github_reviewed_at": "2026-04-08T00:16:45Z"
}
References

Affected packages

npm / hono

Package

Name
hono
View open source insights on deps.dev
Purl
pkg:npm/hono

Affected ranges

Type
SEMVER
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
4.12.12

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-wmmm-f939-6g9c/GHSA-wmmm-f939-6g9c.json"