What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-13 · updated 2026-10-24
• Weakness: CWE-401

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.

Affected products

• honojs node-server: from 2.0.0, < 2.0.10

References

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

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