CVE-2026-111821
Received Received - Intake

Improper Input Validation in Apache ActiveMQ KahaDB

Publication date: 2026-11-04

Last updated on: 2026-11-04

Assigner: Apache Software Foundation

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.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-11-04
Last Modified
2026-11-04
Generated
2026-11-04
AI Q&A
2026-11-04
EPSS Evaluated
N/A
NVD
CVE-2026-111821
EUVD
EUVD-2026-116826

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-20 The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This is an improper input validation vulnerability in Apache ActiveMQ and Apache ActiveMQ KahaDB. It occurs when a user creates a durable subscription with a clientId and subscription name that, when combined, exceed 65,535 characters in length. This causes the broker to shut down and become unrecoverable.

Detection Guidance

To detect this vulnerability, monitor Apache ActiveMQ logs for broker shutdowns or errors related to durable subscriptions with unusually long client IDs or subscription names. Check for messages indicating subscription length exceeding 65,535 characters combined.

Impact Analysis

The vulnerability can cause the Apache ActiveMQ broker to crash and become permanently unavailable. This disrupts message brokering services, leading to downtime and potential loss of critical messaging functionality.

Mitigation Strategies

Immediately upgrade Apache ActiveMQ and Apache ActiveMQ KahaDB to versions 6.4.0, 6.3.3, or 5.19.12 or later. Disable or restrict durable subscription creation until the upgrade is complete.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-111821. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart

Security Radar

News mentioning this vulnerability
Loading related security news...