CVE-2026-40046

CVE-2026-40046: Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ MQTT: Missing fix for CVE-2025-66168: MQTT control packet remaining length field is not properly validated

Vendor Apache Software Foundation
Product Apache ActiveMQ
Weakness CWE-190
Published April 9, 2026
Last update April 10, 2026

CVSS base score

What the vulnerability does

Description

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.

Key dates

Disclosure timeline

April 9, 2026 CVE published
April 10, 2026 Record updated