CVE-2025-66168

5.4 MEDIUM
Published: March 04, 2026 Modified: March 10, 2026
View on NVD

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 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. This issue affects Apache ActiveMQ: before 5.19.2, 6.0.0 to 6.1.8, and 6.2.0 Users are recommended to upgrade to version 5.19.2, 6.1.9, or 6.2.1, which fixes the issue.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://lists.apache.org/thread/13n8mkrb2jf2y6yyhpgrkmpqcm7djyto
Source: security@apache.org
Mailing List Vendor Advisory
http://www.openwall.com/lists/oss-security/2026/03/03/5
Source: af854a3a-2127-422b-91ae-364da2661108
Mailing List Third Party Advisory

2 reference(s) from NVD

Quick Stats

CVSS v3 Score
5.4 / 10.0
EPSS (Exploit Probability)
0.1%
31th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

apache