CVE-2025-55163: Netty

High severity, CVSS 7.5. EPSS: 1.1% chance of exploitation in the next 30 days.

Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.124.Final and 4.2.4.Final, Netty is vulnerable to MadeYouReset DDoS. This is a logical vulnerability in the HTTP/2 protocol, that uses malformed HTTP/2 control frames in order to break the max concurrent streams limit - which results in resource exhaustion and distributed denial of service. This issue has been patched in versions 4.1.124.Final and 4.2.4.Final.

Affected products

• Netty Netty: before 4.1.124 (fixed in 4.1.124); from 4.2.0, before 4.2.4 (fixed in 4.2.4)

Published 2025-08-13. Last modified 2026-06-17.