Path Traversal in Hono
CVE-2026-39407
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.
Vulnerability class: Path Traversal (Directory Traversal)
EPSS: 0.005 (37.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
Affected products
- Hono
- Honojs Hono — versions < 4.12.12
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-39407?
- CVE-2026-39407 is a medium-severity vulnerability in Hono, classified under Path Traversal. CVSS score: 5.3/10. Published 2026-04-08.
- How severe is CVE-2026-39407?
- Medium severity. CVSS v3 base score is 5.3 out of 10.