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.
History

Fri, 21 Aug 2026 13:30:00 +0000

Type Values Removed Values Added
First Time appeared Apple
Apple swiftnio
Vendors & Products Apple
Apple swiftnio

Fri, 21 Aug 2026 02:45:00 +0000

Type Values Removed Values Added
Title Unauthenticated Remote Peer Can Crash NIOWebSocket‑Based Servers with 11‑Byte Frame

Thu, 20 Aug 2026 21:30:00 +0000


Thu, 20 Aug 2026 21:15:00 +0000


Thu, 20 Aug 2026 20:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20
CWE-770
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 20 Aug 2026 19:15:00 +0000

Type Values Removed Values Added
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.
References

cve-icon MITRE

Status: PUBLISHED

Assigner: apple

Published:

Updated: 2026-08-20T21:10:49.702Z

Reserved: 2026-05-01T22:46:21.641Z

Link: CVE-2026-43678

cve-icon Vulnrichment

Updated: 2026-08-20T19:44:38.706Z

cve-icon NVD

Status : Received

Published: 2026-08-20T19:16:52.353

Modified: 2026-08-20T21:17:06.430

Link: CVE-2026-43678

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-21T13:00:48Z