What’s Vulnerable › Vulnerabilities
CVE-2026-43678
- Severity: medium (CVSS 5.3 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-08-20 · updated 2026-10-18
- Weakness: CWE-20
Description
An unauthenticated remote peer can crash any NIOWebSocket-based server (including Vapor and Hummingbird) with a single 11-byte frame sent after a completed WebSocket handshake, dropping all active connections until the process restarts. This vulnerability is addressed in swift-nio version 2.101.0.
Affected products
- Swift Project SwiftNIO: before 2.101.0 — fixed in 2.101.0
How to fix
Upgrade to a fixed version: Swift Project SwiftNIO 2.101.0. Check the vendor advisory for mitigations.
References
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