CVE-2026-59898 Security Details

CVE ID

CVE-2026-59898

CWE

CWE-444

CVE Description

Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, ab attacker can force WebSocket upgrade via the lax V07 (or V08) handshaker by sending `Sec-WebSocket-Version: 7` and omitting `Connection: Upgrade` / `Upgrade: websocket` headers, completing a protocol switch that a proxy would not recognize as an Upgrade request and enabling HTTP request smuggling / protocol-confusion attacks. This issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.

Published

Jul 24, 2026

CVSS Score & Severity

7.5High

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Score

0.249%

Malware

malware

KEV Status

Not in KEV Catalog: No known exploits

Affected Ecosystems

affected

Source

National Vulnerability Database

References

GitHub · netty/nettyPROJECT