Evidence-led vulnerability intelligence · 2026-11-04 15:47 IST

CVE-2026-111821

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.

UNRATED · N/AWeb servers & CMS

Executive briefing

The source record describes: 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. The practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.

Assessment: Potential exposure only — validate the installed product, exact version, configuration and vendor applicability before treating an asset as confirmed vulnerable.

Evidence confidence: Limited Evidence-derived, not an exploitability verdict

Severity & attack characteristics

N/A / 10 ·

CVSS vector:

No CVSS vector is currently available in the source record.

Technical explanation & impact

The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.

Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.

Weakness classification

CWE-20

Affected products and versions

NVD has not supplied machine-readable vulnerable CPE product/version entries for this CVE. This is an information gap, not proof that no products are affected. Check the vendor advisory references below.

Remediation & validation

Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
Validate the remediation with a version check and vulnerability rescan, then retain change evidence.

No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.

Vendor advisories, patches & exploit references

https://lists.apache.org/thread/p8gxq66lmztkrls74wkz3xh9chqd0pwl VENDOR security@apache.org
http://www.openwall.com/lists/oss-security/2026/11/03/19 REFERENCE af854a3a-2127-422b-91ae-364da2661108

Information gaps & confidence notes

These gaps indicate missing source data. CVE Watch does not fill them with guessed product, exploit or patch details.

NVD does not currently provide machine-readable vulnerable CPE product/version entries for this record.
No CVSS vector is currently available in the source record.

Last enrichment: 2026-11-05T07:02:00+00:00 · Source last modified: 2026-11-04T14:10:09.713

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