CVE-2026-111821: Apache ActiveMQ, Apache ActiveMQ KahaDB: Oversized client identifier strings poison the KahaDB journal
CVE-2026-111821 key facts
- CISA KEV
- Not listed (catalogue checked )
- Highest advisory rating
- High
- CVSS base score
- 6.5 (Red Hat)
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H· base score 7.5, scored by CISA-ADPAttack vector: network. Attack complexity: low. Privileges required: none. User interaction: none. Scope: unchanged. Confidentiality impact: none. Integrity impact: none. Availability impact: high.- Weakness
- CWE-20 Improper input validation
- CISA SSVC
- Exploitation: none observed. Automatable: yes. Technical impact: partial. CISA, .
- Fixed releases
- Apache: 6.3.3, 5.19.12
- Red Hat: 6.4.0, 6.3.3, 5.19.12
- Assigned by
- apache (CNA)
- CVE record published
- Listed by VulniPulse
- Record changed
Ratings, versions and fixes are quoted from the vendor advisories that cover only CVE-2026-111821; each belongs to its advisory, not to every product listed. How records are collected and checked.
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.
Text from the CVE.org record (apache).
How do I fix CVE-2026-111821?
Upgrade to a fixed release named by the vendor:
- Apache: 6.3.3, 5.19.12
- Red Hat: 6.4.0, 6.3.3, 5.19.12
- Users are recommended to upgrade to version 6.4.0, 6.3.3 or 5.19.12, which fixes the issue. (Apache)
Vendor advisories for CVE-2026-111821
Apache
1 advisory- Advisory severityHigh
High [CVE-2026-111821] Apache ActiveMQ, Apache ActiveMQ KahaDB: Oversized client identifier strings poison the KahaDB journal
CVE-2026-111821Source published Source updated
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 in this advisory
- Apache ActiveMQ
- Source-reported affected versions
- Apache ActiveMQ 6.0.0 before 6.3.3
- Apache ActiveMQ before 5.19.12
- Apache ActiveMQ KahaDB 6.0.0 before 6.3.3
- Apache ActiveMQ KahaDB before 5.19.12
- Source-reported fixed versions
- 6.3.3
- 5.19.12
- Mitigation guidance
- Users are recommended to upgrade to version 6.4.0, 6.3.3 or 5.19.12, which fixes the issue.
Red Hat
1 advisory- Advisory severityMedium6.5
Medium [CVE-2026-111821] org.apache.activemq/activemq-kahadb-store: activemq-kahadb-store: Denial of Service via oversized durable subscription identifiers
CVE-2026-111821Source published Source updated
org.apache.activemq/activemq-kahadb-store: activemq-kahadb-store: Denial of Service via oversized durable subscription identifiers. Red Hat rates this moderate (CVSS 6.5). Weakness: CWE-248. Affected product named by the advisory: Red Hat Fuse 7.
- Related products — impact not confirmed
- Red Hat Fuse 7
- Source-reported affected versions
- < 6.0.0
- < 6.3.3
- < 5.19.12
- Source-reported fixed versions
- 6.4.0
- 6.3.3
- 5.19.12
- Mitigation guidance
- No mitigation guidance extracted; consult the source.
References
- CVE-2026-111821 recordCVE.org
- CVE-2026-111821 detailNVD
- lists.apache.org/thread/p8gxq66lmztkrls74wkz3xh9chqd0pwlvendor-advisory
Timeline
- CVE record published
- First vendor advisory listed by VulniPulse
- CVE record last updated
More Apache advisories
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