Detections
Analytics

Apache ActiveMQ < 5.19.2 / 6.0.x < 6.1.9 / 6.2.0 MQTT Control Packet Validation Vulnerability (CVE-2025-66168)

medium Nessus Plugin ID 300913

Synopsis

The remote host is running a web application that is affected by a vulnerability.

Description

The version of Apache ActiveMQ running on the remote host is prior to 5.19.2, 6.0.x prior to 6.1.9, or 6.2.0. It is, therefore, affected by a vulnerability:

 - Apache ActiveMQ does not properly validate the remaining length field in MQTT control packets which may lead to an integer overflow during the decoding of malformed packets. When this integer overflow occurs, ActiveMQ may incorrectly compute the total Remaining Length and subsequently misinterpret the payload as multiple MQTT control packets which makes the broker susceptible to unexpected behavior when interacting with non-compliant clients. This behavior violates the MQTT v3.1.1 specification, which restricts Remaining Length to a maximum of 4 bytes. The scenario occurs on established connections after the authentication process. Brokers that are not enabling mqtt transport connectors are not impacted.
 (CVE-2025-66168)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade to Apache ActiveMQ version 5.19.2, 6.1.9, or 6.2.1 or later.

See Also

http://www.nessus.org/u?8c9c5f41

Plugin Details

Severity: Medium

ID: 300913

File Name: activemq_6_2_1.nasl

Version: 1.1

Type: combined

Agent: unix

Family: CGI abuses

Published: 3/5/2026

Updated: 3/5/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Enable CGI Scanning: true

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 5.5

Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:N

CVSS Score Source: CVE-2025-66168

CVSS v3

Risk Factor: Medium

Base Score: 5.4

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Vulnerability Information

CPE: cpe:/a:apache:activemq

Required KB Items: installed_sw/Apache ActiveMQ

Patch Publication Date: 3/4/2026

Vulnerability Publication Date: 3/4/2026

Reference Information

CVE: CVE-2025-66168