CVE-2026-76816
Fixed in a distro release EPSS <1%CVSS 3.5
Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.137.Final and 4.2.17.Final, MqttEncoder does not validate client identifiers, will topics, usernames, and PUBLISH topic names before encoding, allowing prohibited null bytes in MQTT UTF-8 string fields and potentially causing routing, access-control, or identity mismatches in downstream brokers. The vulnerability is exploitable when an application uses Netty's MQTT encoder to construct messages from user-controlled input. This issue is fixed in versions 4.1.137.Final and 4.2.17.Final.
Products: netty
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Debian 12 | netty | no fix |
| Debian 13 | netty | no fix |
| Debian 14 | netty | no fix |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise Module for Package Hub 15 SP7 | netty | 4.1.138-150200.4.56.1 |
| SUSE Linux Enterprise Server 15 SP4-LTSS | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise Server 15 SP5-LTSS | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise Server 15 SP6-LTSS | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | netty-tcnative | 2.0.84-150200.3.51.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | netty-tcnative | 2.0.84-150200.3.51.1 |
| Ubuntu 26.10 | netty | no fix |
| Ubuntu Pro 14.04 LTS | netty | no fix |
| Ubuntu Pro 16.04 LTS | netty | no fix |
| Ubuntu Pro 18.04 LTS | netty | no fix |
| Ubuntu Pro 20.04 LTS | netty | no fix |
| Ubuntu Pro 22.04 LTS | netty | no fix |
| Ubuntu Pro 24.04 LTS | netty | no fix |
| Ubuntu Pro 26.04 LTS | netty | no fix |
| openSUSE Tumbleweed | netty | 4.1.138-1.1 |