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Fencer Vulns
high 7.5

CVE-2026-40046 json

Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ MQTT: Missing fix for CVE-2025-66168: MQTT control packet remaining length field is not properly validated

published 2026-04-09 7 mo ago modified 2026-10-26 14 d ago also BIT-activemq-2026-40046 , EUVD-2026-20956 , GHSA-xvqc-pp94-fmpx

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

Integer Overflow or Wraparound vulnerability in Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ MQTT.

The fix for "CVE-2025-66168: MQTT control packet remaining length field is not properly validated" was only applied to 5.19.2 (and future 5.19.x) releases but was missed for all 6.0.0+ versions.

This issue affects Apache ActiveMQ: from 6.0.0 before 6.2.4; Apache ActiveMQ All: from 6.0.0 before 6.2.4; Apache ActiveMQ MQTT: from 6.0.0 before 6.2.4.

Users are recommended to upgrade to version 6.2.4 or a 5.19.x version starting with 5.19.2 or later (currently latest is 5.19.5), which fixes the issue.

Patch / fix

  • maven org.apache.activemq:apache-activemq 6.2.4
  • maven org.apache.activemq:activemq-all 6.2.4
  • maven org.apache.activemq:activemq-mqtt 6.2.4
  • bitnami activemq 6.2.4
  • Apache Software Foundation Apache ActiveMQ 6.2.4
  • Apache Software Foundation Apache ActiveMQ All 6.2.4
  • Apache Software Foundation Apache ActiveMQ MQTT 6.2.4

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-40046 updated cvss 5.4

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-2025

  • Red Hat Fuse 7 activemq-all, activemq-mqtt Red Hat JBoss Enterprise Application Platform 7 activemq-mqtt Red Hat JBoss Enterprise Application Platform Expansion Pack activemq-mqtt
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
maven org.apache.activemq:apache-activemq
>=6.0.0, <6.2.4
6.2.4
maven org.apache.activemq:activemq-all
>=6.0.0, <6.2.4
6.2.4
maven org.apache.activemq:activemq-mqtt
>=6.0.0, <6.2.4
6.2.4
bitnami activemq
>=6.0.0, <6.2.4
6.2.4

Affected products

  • Apache Software Foundation Apache ActiveMQ
  • Apache Software Foundation Apache ActiveMQ All
  • Apache Software Foundation Apache ActiveMQ MQTT

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.