CVSS 3.1
5.3 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NCVE-2026-126357
Hono: `mount()` and `app.mount()` can forward a path that bypasses middleware scoped inside the mount prefix
Medium (5.3) in honojs hono. Fixed in hono 4.13.16.
On this page
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.13.16, mount() and app.mount() can remove a dynamic mount prefix using the route-pattern length rather than the matched-prefix length, allowing a crafted path to be forwarded as a protected inner route while the outer application routes the original path. Since 4.12.21, rebuilding the forwarded URL from the decoded pathname can also convert a decoded backslash to a slash and collapse parent-directory segments, again causing the mounted application to receive a protected path. An unauthenticated client can use either applicable path transformation to reach a mounted route without authentication or authorization middleware scoped to a subpath inside the mount prefix. This issue is fixed in version 4.13.16.
Severity
- CWE
- CWE-288 Authentication Bypass Using an Alternate Path or Channel
- OWASP Top 10
- A07:2025 Authentication Failures
- Published
- Assigned by
- GitHub_M (CNA)
- NVD analysis
- Not in the NVD yet
- Record from
- the CVE List, synced
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| honojs hono | < 4.13.16 |
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-4m76-xfj5-7975 | npm | hono | <4.13.16 | 4.13.16 |
Attack patterns (CAPEC)
- CAPEC-127 Directory Indexing Likelihood: High · Severity: Medium
- CAPEC-665 Exploitation of Thunderbolt Protection Flaws Likelihood: Low · Severity: Very High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.