SEPTEMBER 15, 2026
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Case File

CVE-2026-76816

LOW · CVSS 3.5 EPSS 0.17% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-08-24 · Last synced 2026-09-15

CyberRota Analysis

AI-Generated

Netty's MQTT encoder prior to versions 4.1.137.Final and 4.2.17.Final is vulnerable due to inadequate validation of client identifiers, will topics, usernames, and PUBLISH topic names, allowing the inclusion of null bytes in MQTT UTF-8 string fields. This can lead to routing, access-control, or identity mismatches in downstream brokers, posing a risk to applications that utilize user-controlled input for message construction. Developers and organizations using affected versions of Netty should prioritize upgrading to the patched versions to mitigate potential exploitation.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
exploit

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-76816
Severity
LOW
CVSS
3.5
EPSS
0.17%

Original NVD Description

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.