Integer overflow in Apache Software Foundation Activemq
CVE-2026-40046
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.
Vulnerability class: Integer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (47.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 47.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002
Affected products
- Apache Software Foundation Activemq — versions 6.0.0
- Apache Software Foundation Activemq All — versions 6.0.0
- Apache Software Foundation Activemq Mqtt — versions 6.0.0
Weakness classification (CWE)
References
- www.cve.org/CVERecord (related)
- activemq.apache.org/security-advisories.data/CVE-2026-40046-announcement.txt (vendor-advisory)
- lists.apache.org/thread/zdntj5rcgjjzrpow84o339lzldy68zrg (vendor-advisory)
Frequently asked questions
- What is CVE-2026-40046?
- CVE-2026-40046 is a high-severity vulnerability in Apache Software Foundation Activemq, classified under Integer Overflow or Wraparound. CVSS score: 7.5/10. Published 2026-04-09.
- How severe is CVE-2026-40046?
- High severity. CVSS v3 base score is 7.5 out of 10.