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OpenAdvisories
High · 7.5 CVE-2026-111821 EUVD-2026-116826GHSA-c86r-9hm3-5pcc

Apache ActiveMQ, Apache ActiveMQ KahaDB: Oversized client identifier strings poison the KahaDB journal

Published Nov 4, 2026 · Updated Nov 10, 2026 · Assigned by apache

Description

Improper input validation vulnerability in Apache ActiveMQ, Apache ActiveMQ KahaDB.

A user can create a durable subscription with a clientId and subscription name that have a combined length > 65,535 (while separately being shorter) on a broker using KahaDB which can cause the broker to shutdown and be unrecoverable. 

This issue affects Apache ActiveMQ: from 6.0.0 before 6.3.3, before 5.19.12; Apache ActiveMQ KahaDB: from 6.0.0 before 6.3.3, before 5.19.12.

Users are recommended to upgrade to version 6.4.0, 6.3.3 or 5.19.12, which fixes the issue.

Affected products

VendorProductAffectedFixed
Apache Software Foundation Apache ActiveMQ 6.0.0 – < 6.3.3, < 5.19.12 6.3.3
Apache Software Foundation Apache ActiveMQ KahaDB 6.0.0 – < 6.3.3, < 5.19.12 6.3.3

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 13 activemq No fix yet —
Debian 12 activemq No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 activemq No fix yet —
Ubuntu 26.04 LTS activemq No fix yet —
Ubuntu 24.04 LTS activemq No fix yet —
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 22.04 LTS activemq No fix yet —
Ubuntu Pro 20.04 LTS activemq No fix yet —
Ubuntu Pro 18.04 LTS activemq No fix yet —
Ubuntu Pro 16.04 LTS activemq No fix yet —

Advisories 1

References