---
id: CVE-2026-84365
title: >-
  Hono is a Web application framework that provides support for any JavaScript
  runtime
summary: >-
  Hono is a Web application framework that provides support for any JavaScript
  runtime. From 4.12.12 until 4.13.5, the fix released for CVE-2026-39408 does
  not cover every traversal sequence, and toSSG() can still write files outside
  the c…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N'
cwe:
  - CWE-22
vendor: hono
product: hono
affected:
  - hono < 4.13.5
patched:
  - hono 4.13.5
published: '2026-09-01'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T21:09:13.080'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84365'
references:
  - url: >-
      https://github.com/honojs/hono/commit/3a67f7f3997e1437d108f7bcba2dbcee2df69221
    label: security-advisories@github.com
  - url: 'https://github.com/honojs/hono/releases/tag/v4.13.5'
    label: security-advisories@github.com
  - url: 'https://github.com/honojs/hono/security/advisories/GHSA-gqvv-2mrq-wpjv'
    label: security-advisories@github.com
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84365'
  - url: 'https://github.com/advisories/GHSA-gqvv-2mrq-wpjv'
tags:
  - nvd
  - ghsa
  - npm
epss: 0.00437
epssPercentile: 0.35402
aliases:
  - GHSA-gqvv-2mrq-wpjv
ecosystem: npm
ingestedAt: '2026-09-08T22:12:30.968Z'
---

## Overview

Hono is a Web application framework that provides support for any JavaScript runtime. From 4.12.12 until 4.13.5, the fix released for CVE-2026-39408 does not cover every traversal sequence, and toSSG() can still write files outside the configured output directory when a route parameter contains consecutive parent-directory segments. Static site generation builds each output path from the route path and values supplied through ssgParams, then verifies that the result stays inside the output directory using the same normalization routine that built the path. That routine does not fully collapse runs of consecutive parent-directory segments, allowing a path that the check accepts to resolve outside the output directory, and the check also treats output directories that differ in how they are rooted as equivalent. This arises when an application generates a static site from route parameter values it does not fully control, such as slugs from a CMS, API, or user submission. An untrusted ssgParams value can create or overwrite files elsewhere in the build environment and alter generated artifacts or deployment output. The vulnerability affects build-time static site generation only; request-time routing and applications with entirely developer-controlled ssgParams values are not affected. This issue is fixed in version 4.13.5.

## Remediation

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

## Package advisory (CVE-2026-84365)

Affected packages:

- `hono < 4.13.5`

Patched in:

- `hono 4.13.5`

Source: https://github.com/advisories/GHSA-gqvv-2mrq-wpjv