GitHub Advisoryadvisory · Maven

GHSA-4mp9-239f-g9hg Netty: WebSockets V07/V08 handshaker missing Connection/Upgrade validation

MEDIUM Published 2026-07-22 Modified 2026-07-22 Official page ↗
Aliases
CVE-2026-59898
Ecosystem
Maven
Packages
io.netty:netty-codec-http
Severity
Moderate
CVSS vector
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Weaknesses
CWE-444
Reviewed
2026-07-22

Affected packages

• Maven io.netty:netty-codec-http: >= 4.2.0.Final, < 4.2.16.Final → fixed in 4.2.16.Final • Maven io.netty:netty-codec-http: < 4.1.136.Final → fixed in 4.1.136.Final

Description

Summary An 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.

Related

Alias · CVE (1)

  • CVE-2026-59898 Netty is an asynchronous, event-driven network application framework. vulnerability

Weakness · CWE (1)

  • CWE-444 Inconsistent Interpretation of HTTP Requests weakness

References