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CVE-2026-76816

CVE-2026-76816 · Netty: MQTT Topic Name and Client ID Validation Bypass

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 3.5 · Low · EPSS 0.2%

Published
Updated

Stack: system

Affected products and versions

  • netty

    Versions
    • >= 4.2.0.Final, < 4.1.137.Final: Affected
    • < 4.1.137.Final: Affected

    No fix published

  • netty Debian:12

    Versions
    • 1:4.1.48-10
    • 1:4.1.48-11
    • 1:4.1.48-12
    • 1:4.1.48-13
    • 1:4.1.48-14
    • 1:4.1.48-15
    • 1:4.1.48-16
    • 1:4.1.48-7
    • 1:4.1.48-7+deb12u1
    • 1:4.1.48-7+deb12u2
    • 1:4.1.48-8
    • 1:4.1.48-9
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • netty Debian:13

    Versions
    • 1:4.1.48-10
    • 1:4.1.48-10+deb13u1
    • 1:4.1.48-11
    • 1:4.1.48-12
    • 1:4.1.48-13
    • 1:4.1.48-14
    • 1:4.1.48-15
    • 1:4.1.48-16
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • netty Debian:14

    Versions
    • 1:4.1.48-10
    • 1:4.1.48-11
    • 1:4.1.48-12
    • 1:4.1.48-13
    • 1:4.1.48-14
    • 1:4.1.48-15
    • 1:4.1.48-16
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • netty Ubuntu:Pro:14.04:LTS

    Versions
    • 1:3.2.6.Final-2
    • 1:3.2.6.Final-2+deb8u2build0.14.04.1~esm1
    • 1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • netty Ubuntu:Pro:16.04:LTS

    Versions
    • 1:3.2.6.Final-2
    • 1:4.0.32-1
    • 1:4.0.33-1
    • 1:4.0.34-1
    • 1:4.0.34-1ubuntu0.1~esm1
    • 1:4.0.34-1ubuntu0.1~esm2
    • 1:4.0.34-1ubuntu0.1~esm3
    • 1:4.0.34-1ubuntu0.1~esm4
    • 1:4.0.34-1ubuntu0.1~esm5
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • netty Ubuntu:Pro:18.04:LTS

    Versions
    • 1:4.1.7-4
    • 1:4.1.7-4ubuntu0.1~esm1
    • 1:4.1.7-4ubuntu0.1
    • 1:4.1.7-4ubuntu0.1+esm1
    • 1:4.1.7-4ubuntu0.1+esm2
    • 1:4.1.7-4ubuntu0.1+esm3
    • 1:4.1.7-4ubuntu0.1+esm4
    • 1:4.1.7-4ubuntu0.1+esm5
    • 1:4.1.7-4ubuntu0.1+esm6
    • 1:4.1.7-4ubuntu0.1+esm7
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • netty Ubuntu:Pro:20.04:LTS

    Versions
    • 1:4.1.33-1
    • 1:4.1.33-2
    • 1:4.1.33-3
    • 1:4.1.45-1
    • 1:4.1.45-1ubuntu0.1~esm1
    • 1:4.1.45-1ubuntu0.1~esm2
    • 1:4.1.45-1ubuntu0.1~esm3
    • 1:4.1.45-1ubuntu0.1~esm4
    • 1:4.1.45-1ubuntu0.1~esm6
    • 1:4.1.45-1ubuntu0.1~esm7
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • netty Ubuntu:Pro:22.04:LTS

    Versions
    • 1:4.1.48-4
    • 1:4.1.48-4+deb11u1build0.22.04.1
    • 1:4.1.48-4+deb11u2build0.22.04.1
    • 1:4.1.48-4+deb11u2ubuntu0.1~esm1
    • 1:4.1.48-4+deb11u2ubuntu0.1~esm2
    • 1:4.1.48-4+deb11u2ubuntu0.1
    • 1:4.1.48-4+deb11u2ubuntu0.1+esm1
    • 1:4.1.48-4+deb11u2ubuntu0.1+esm3
    • 1:4.1.48-4+deb11u2ubuntu0.2
    • 1:4.1.48-4+deb11u2ubuntu0.2+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • netty Ubuntu:Pro:24.04:LTS

    Versions
    • 1:4.1.48-7
    • 1:4.1.48-8
    • 1:4.1.48-9
    • 1:4.1.48-9ubuntu0.1~esm1
    • 1:4.1.48-9ubuntu0.1~esm2
    • 1:4.1.48-9ubuntu0.1
    • 1:4.1.48-9ubuntu0.1+esm1
    • 1:4.1.48-9ubuntu0.1+esm3
    • 1:4.1.48-9ubuntu0.2
    • 1:4.1.48-9ubuntu0.2+esm1
    • 1:4.1.48-9ubuntu0.2+esm2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • netty Ubuntu:26.10

    Versions
    • 1:4.1.48-16
    • 1:4.1.48-16ubuntu1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • netty Ubuntu:Pro:26.04:LTS

    Versions
    • 1:4.1.48-10
    • 1:4.1.48-11
    • 1:4.1.48-12
    • 1:4.1.48-13
    • 1:4.1.48-14
    • 1:4.1.48-16
    • 1:4.1.48-16ubuntu0.1~esm2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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