CVE-2026-59898
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.
Is your site exposed to CVE-2026-59898?
Run a free security scan — no signup, results in seconds.
Weakness Type (CWE)
References
Frequently Asked Questions
What is CVE-2026-59898? +
How do I check if I'm vulnerable to CVE-2026-59898? +
Related Vulnerabilities
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in ithewei libhv allows HTTP Response Smuggling.This issue affects libhv: through …
HTTP request desynchronization in Ping Identity PingAccess, all versions prior to 8.0.1 affected allows an attacker to send specially crafted …
This vulnerability allows a high-privileged authenticated PAM user to achieve remote command execution on the affected PAM system by sending …
An HTTP Request Smuggling [CWE-444] vulnerability in the Authentication portal of WatchGuard Fireware OS allows a remote attacker to evade …
Connection desynchronization between an HTTP proxy and the model backend. The fixes were rolled out for all proxies in front …
Member Login Script 3.3 contains a client-side desynchronization vulnerability that allows attackers to manipulate HTTP request handling by exploiting Content-Length …