---
id: CVE-2026-84364
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. Prior to 4.13.5, when parseBody() expands dot-separated form field
  names into nested objects with dot-notation parsing enabled, it does not limit
  the n…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-400
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-2026-84364'
references:
  - url: >-
      https://github.com/honojs/hono/commit/531e9c5a3ae058d10de33f643055bd4009a87178
    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-g6gw-c38x-mqfc'
    label: security-advisories@github.com
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84364'
  - url: 'https://github.com/advisories/GHSA-g6gw-c38x-mqfc'
tags:
  - nvd
  - ghsa
  - npm
epss: 0.00529
epssPercentile: 0.42338
aliases:
  - GHSA-g6gw-c38x-mqfc
ecosystem: npm
ingestedAt: '2026-09-08T22:12:30.968Z'
---

## Overview

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.13.5, when parseBody() expands dot-separated form field names into nested objects with dot-notation parsing enabled, it does not limit the nesting depth or the total number of intermediate objects created. Empty segments are preserved, so one deeply dotted field name can encode one nesting level per byte, while a large number of shallowly dotted fields can create the same amplification across a request. A request body within a normal size limit can therefore allocate an object graph far larger than the request after the body has already been accepted. An unauthenticated attacker who can reach an affected endpoint can send concurrent requests that exhaust the JavaScript heap, terminate the server process, and leave the service unavailable until restart. Dot-notation parsing is not enabled by default, and applications using the default behavior 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-2026-84364)

Affected packages:

- `hono < 4.13.5`

Patched in:

- `hono 4.13.5`

Source: https://github.com/advisories/GHSA-g6gw-c38x-mqfc