High · published May 13, 2026
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's DNS codec does not enforce RFC 1035 domain name constraints during either encoding or decoding. This creates a bidirectional attack surface: malicious DNS responses can exploit the decoder, and user-influenced hostnames can exploit the encoder. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
| Product | Versions | Fixed in |
|---|---|---|
| netty/netty | < 4.1.133 | 4.1.133 |
| netty/netty | ≥ 4.2.0, < 4.2.13 | 4.2.13 |