High · published March 28, 2026
Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.132.Final and 4.2.10.Final, a remote user can trigger a Denial of Service (DoS) against a Netty HTTP/2 server by sending a flood of `CONTINUATION` frames. The server's lack of a limit on the number of `CONTINUATION` frames, combined with a bypass of existing size-based mitigations using zero-byte frames, allows an user to cause excessive CPU consumption with minimal bandwidth, rendering the server unresponsive. Versions 4.1.132.Final and 4.2.10.Final fix the issue.
| Product | Versions | Fixed in |
|---|---|---|
| netty/netty | < 4.1.132 | 4.1.132 |
| netty/netty | ≥ 4.2.0, < 4.2.10 | 4.2.10 |