PT-2026-63546
CVE-2026-59898
·
Published
2026-07-22
·
Updated
2026-10-12
Description by
CVSS 3.1
9.8
CriticalMetricsAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Name of the Vulnerable Software and Affected Versions
Netty versions prior to 4.1.136.Final
Netty versions prior to 4.2.16.Final
Description
An attacker can force a WebSocket upgrade through the lax V07 or V08 handshaker. By sending the
Sec-WebSocket-Version: 7 header and omitting the Connection: Upgrade and Upgrade: websocket headers, a protocol switch is completed. Because a proxy would not recognize this as an Upgrade request, it enables protocol-confusion and HTTP request smuggling attacks.Recommendations
Update to version 4.1.136.Final.
Update to version 4.2.16.Final.
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