CVE-2026-76816

Severity CVSS v4.0:

Pending analysis

Type:

CWE-20 Input Validation

Publication date:

24/08/2026

Last modified:

25/08/2026

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&#39;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.

Impact

Vector 3.x

CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N CVSS v3.1 Severity and Metrics:

Base Score: 3.50 LOW
Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Attack Vector (AV): Adjacent
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): Low
Availability (A): None

Base Score 3.x

3.50

Severity 3.x

LOW

CVE-2026-76816

Description

Impact

References to Advisories, Solutions, and Tools