Packages / @hono/node-server / Security

ModerateVulnerabilityGHSA-9mqv-5hh9-4cggCVE-2026-73565Published 21 Jul 2026

Node.js Adapter for Hono: Unauthenticated memory-leak DoS via aborted WebSocket handshake

Affected releases · @hono/node-server

  • 2.x2.0.0 – 2.0.9Fixed in 2.0.10

On 2.x, the newest line:

npm install @hono/node-server@2.0.10

  1. Not affected

    0.2.0 – 1.19.17

    84 releases

  2. Affected

    2.0.0 – 2.0.9

    9 releases

  3. Fixed

    2.0.10 – 2.1.5

    9 releases, latest

102 stable releases of @hono/node-server, oldest to newest.

Is your project affected?

Paste your package.json, or type the range you declare for @hono/node-server. It is read in your browser and sent nowhere.

What happens

Summary

A WebSocket upgrade request to an upgradeWebSocket route with a missing or malformed Sec-WebSocket-Key header leaks memory permanently. The request's IncomingMessage is retained in an internal map and a pending promise is never settled, even though no connection is established. Since the route is reachable pre-handshake without authentication, an unauthenticated attacker can flood it to gradually exhaust memory.

Details

The built-in WebSocket helper cleans up its internal map only on a successful handshake or when the route guard rejects the request. When ws aborts the handshake because Sec-WebSocket-Key is missing or malformed, no connection event is emitted, so neither cleanup path runs and the entry is retained forever. A present-but-malformed key leaks identically, so a proxy that only checks for the header's presence does not mitigate it.

Impact

An unauthenticated attacker can flood any public upgradeWebSocket route with malformed-key upgrade requests, causing unbounded memory growth and eventual loss of availability. No confidentiality or integrity impact.

Reported by @TarPeg007.