# CVE-2026-111757: Hono: `serveStatic` decodes the request path a second time, leading to bypass of middleware on static paths

> Attackers can bypass middleware protections to read unauthorized static files in Hono applications using malformed percent-encoded paths.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Oct 2026
- **Updated:** 20 Oct 2026
- **Also known as:** ECHO-693e-a60e-a833, MINI-wjxm-889f-3j4g

## What is CVE-2026-111757?

CVE-2026-111757 is a medium-severity path traversal vulnerability in honojs hono, published on 19 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-174 (Double Decoding of the Same Data)

## Which versions are affected by CVE-2026-111757?


## How do I fix CVE-2026-111757?

Upgrade to a fixed version.

## Is CVE-2026-111757 being exploited?

There is no known exploitation of CVE-2026-111757 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-111757 and fix it if it is affected.

What it is: CVE-2026-111757 is a medium-severity path traversal vulnerability in honojs hono, published on 19 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-111757 in the wild and no public exploit code.

Affected product: honojs hono. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-111757/ (Markdown: https://insights.sbomify.com/CVE-2026-111757/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-111757
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-111757
- OSV: https://osv.dev/vulnerability/CVE-2026-111757

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-111757/
Summaries are generated and may contain mistakes; the official description above is the record.