Hono: `serveStatic` decodes the request path a second time, leading to bypass of middleware on static paths
Hono is a Web application framework that provides support for any JavaScript runtime. From 4.12.4 until 4.13.11, serveStatic can interpret a malformed percent-encoded path differently from upstream routing middleware and bypass protection for a static prefix. The root cause is serveStatic decodes a routed request path a second time before filesystem lookup. The attack mechanism is malformed percent encoding survives the first routing interpretation and becomes a protected path only during the later static-file decode. The affected component is serveStatic. The trigger conditions are an application protects a static prefix with upstream middleware and serveStatic receives an attacker-controlled malformed percent-encoded path. The impact is unauthorized disclosure of a static file that upstream middleware was intended to protect. The issue does not permit traversal outside the configured static root. This issue is fixed in version 4.13.11.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-109955US | medium5.3 | — | ||
Hono from 4.12.4 before 4.13.11 contains a middleware bypass vulnerability in serveStatic that allows unauthenticated attackers to skip prefix middleware by exploiting double path… | ||||
references
External citations — patches, advisories, analysis.
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/111xxx/CVE-2026-111757.jsonADVISORY
- https://github.com/honojs/hono/commit/8b05c774ef1555c70f5ba5e2991b7e77cc3635ccFIX
- https://github.com/honojs/hono/security/advisories/GHSA-5r4p-p66f-jhc7ADVISORY
- https://nvd.nist.gov/vuln/detail/CVE-2026-111757ADVISORY
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