CVE-2026-111821: Apache ActiveMQ KahaDB vulnerable to oversized client identifier poisoning (CVE-2026-111821)
Combined clientId and subscription name exceeding 65,535 bytes can poison the KahaDB journal in versions before 6.3.3 and 5.19.12.
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CVE-2026-111821
Improper input validation in Apache ActiveMQ KahaDB durable subscriptions
- CVSS 3.1
- 7.5 high
- EPSS
- —
- Published
- ·
- Modified
AI analysisSummaries by Vani AI
Apache ActiveMQ and KahaDB have a vulnerability where users can create durable subscriptions with clientId and subscription name separately under 65,535 characters but combined over this limit on KahaDB brokers. This causes unrecoverable broker shutdown. Affected are versions 6.0.0 before 6.3.3 and before 5.19.12.
What to do: Upgrade to Apache ActiveMQ 6.4.0, 6.3.3 or 5.19.12.
| Product | Affected | Fixed in |
|---|---|---|
| Apache ActiveMQ | 6.0.0 before 6.3.3, before 5.19.12 | 6.4.0, 6.3.3 or 5.19.12 |
| Apache ActiveMQ KahaDB | 6.0.0 before 6.3.3, before 5.19.12 | 6.4.0, 6.3.3 or 5.19.12 |
Estimated exposure
No basis for an estimate.
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Description · NVD
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.
- Weakness
- CWE-20
- Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H