---
id: CVE-2026-73565
title: '@hono/node-server allows running the Hono application on Node.js'
summary: >-
  @hono/node-server allows running the Hono application on Node.js. From 2.0.0
  until 2.0.10, a WebSocket upgrade request to an upgradeWebSocket route with a
  missing or malformed Sec-WebSocket-Key header causes src/websocket.ts to
  retain th…
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-401
  - CWE-770
vendor: honojs
product: node-server
affected:
  - 'node-server >= 2.0.0, < 2.0.10'
published: '2026-08-13'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T20:30:11.423'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-73565'
references:
  - url: >-
      https://github.com/honojs/node-server/commit/3a21938c418340e980cb7ffa88e78369f78392d1
    label: security-advisories@github.com
  - url: 'https://github.com/honojs/node-server/releases/tag/v2.0.10'
    label: security-advisories@github.com
  - url: >-
      https://github.com/honojs/node-server/security/advisories/GHSA-9mqv-5hh9-4cgg
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-08-14T16:45:01.113756Z'
ingestedAt: '2026-09-13T05:23:43.026Z'
epss: 0.00529
epssPercentile: 0.42256
---

## Overview

@hono/node-server allows running the Hono application on Node.js. From 2.0.0 until 2.0.10, a WebSocket upgrade request to an upgradeWebSocket route with a missing or malformed Sec-WebSocket-Key header causes src/websocket.ts to retain the request's IncomingMessage in waiterMap and leave waitForWebSocket pending because ws.handleUpgrade emits no connection event. The aborted handshake therefore has no cleanup path, allowing an unauthenticated attacker to flood a public route, cause unbounded memory growth, and eventually make the service unavailable. This issue is fixed in version 2.0.10.

## Remediation

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