CVE Catalog

CVE-2026-43678

MediumCVSS 5.3
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.29%

21th percentile - higher than 21% of all known CVEs

Summary

An unauthenticated remote attacker 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.

Risk Assessment

The attack can cause service disruption, leading to unavailability of applications and loss of connections for all users. It requires manual process restart, potentially resulting in downtime and reduced service availability.

Recommendation

It is recommended to immediately update swift-nio to version 2.101.0 or later to eliminate the server crash vulnerability.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS