CVE-2026-73565

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

MEDIUM
5.3
CVSS Score
Published: August 13, 2026 at 05:37 PM UTC
Updated: October 24, 2026 at 03:10 PM UTC
1 product affected across 1 vendorNode Server

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

>= 2.0.0, < 2.0.10
Affected range stops below 2.0.10, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-401CWE-770

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