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VULNERABILITIES

CVE-2026-59898 Details

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.

Metrics

CVSS 3.x Severity and Vector Strings:

NIST: [email protected]CVSS-B:7.5 HIGHVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References to Advisories, Solutions, and Tools

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URLSource(s)Tag(s)
https://github.com/netty/netty/releases/tag/netty-4.1.136.Final [email protected]Release Notes
https://github.com/netty/netty/releases/tag/netty-4.2.16.Final [email protected]Release Notes
https://github.com/netty/netty/security/advisories/GHSA-4mp9-239f-g9hg [email protected]Vendor Advisory

Weakness Enumeration

CWE-IDCWE NameSource
CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')[email protected]

Affected Products

ProductVersions
netty netty
< 4.1.136
>= 4.2.0, < 4.2.16

CPE

  • cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*

Remediation

  • No remediation found in references.

Change History

3 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-59898
NVD Published Date:
Jul 29, 2026
NVD Last Modified:
Aug 6, 2026
Source:
[email protected]