---
id: CVE-2026-109955
title: >-
  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 decoding
summary: >-
  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 decoding. Attackers can send malformed percent-encoded
  pa…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-174
  - CWE-551
published: '2026-10-13'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T14:17:34.467'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-109955'
references:
  - url: 'https://github.com/honojs/hono/security/advisories/GHSA-5r4p-p66f-jhc7'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/hono-4.12.4-before-4.13.11-middleware-bypass-via-servestatic-double-decoding
    label: disclosure@vulncheck.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-109955.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-109955'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2550544'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-109955'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-109955'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ingestedAt: '2026-10-13T14:29:01.854Z'
vendor: honojs
product: hono
affected:
  - hono >= 4.12.4 < 4.13.11
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-13T13:51:31.306804Z'
epss: 0.00315
epssPercentile: 0.24239
---

## Overview

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 decoding. Attackers can send malformed percent-encoded paths that the router matches in encoded form, reaching static files without authentication checks running.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Migration Toolkit for Applications 8, Red Hat Ansible Automation Platform 2, Red Hat Enterprise Linux 10, Red Hat Hardened Images, Red Hat OpenShift AI (RHOAI), Red Hat OpenShift Dev Spaces · no fix planned: Migration Toolkit for Applications 8, Red Hat Ansible Automation Platform 2, Red Hat Enterprise Linux 10, Red Hat OpenShift AI (RHOAI), … · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-109955.json)