CVE-2025-66168

Severity
8.8HIGH
EPSS
0.1%
top 78.88%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedMar 4
Latest updateApr 9

Description

Apache ActiveMQ does not properly validate the remaining length field which may lead to an 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 Lengt

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:NExploitability: 2.8 | Impact: 2.5

Affected Packages9 packages

Mavenorg.apache.activemq:activemq-mqtt6.0.06.1.9+2
NVDapache/activemq6.0.06.1.8+2
Mavenorg.apache.activemq:activemq-all6.0.06.1.9+2

🔴Vulnerability Details

4
GHSA
Apache ActiveMQ is Vulnerable to Integer Overflow or Wraparound2026-03-04
OSV
CVE-2025-66168: Apache ActiveMQ does not properly validate the remaining length field which may lead to an overflow during the decoding of malformed packets2026-03-04
OSV
Apache ActiveMQ is Vulnerable to Integer Overflow or Wraparound2026-03-04
CVEList
Apache ActiveMQ, Apache ActiveMQ All Module, Apache ActiveMQ MQTT Module: MQTT control packet remaining length field is not properly validated2026-03-04

📋Vendor Advisories

3
Red Hat
org.apache.activemq/apache-activemq: org.apache.activemq/activemq-all: org.apache.activemq/activemq-mqtt: MQTT control packet remaining length field is not properly validated (missing fix for CVE-20252026-04-09
Red Hat
org.apache.activemq/apache-activemq: org.apache.activemq/activemq-all: org.apache.activemq/activemq-mqtt: Apache ActiveMQ: Unexpected behavior due to integer overflow in MQTT packet decoding2026-03-04
Debian
CVE-2025-66168: activemq - Apache ActiveMQ does not properly validate the remaining length field which may ...2025

🕵️Threat Intelligence

1
Wiz
CVE-2025-66168 Impact, Exploitability, and Mitigation Steps | Wiz

💬Community

1
Bugzilla
CVE-2026-40046 org.apache.activemq/apache-activemq: org.apache.activemq/activemq-all: org.apache.activemq/activemq-mqtt: MQTT control packet remaining length field is not properly validated (missing f2026-04-09