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Fencer Intel
high —

CVE-2026-111821 json

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

published 5d ago modified 5d ago also EUVD-2026-116826

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

Summary

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.

Patch / fix

  • Apache Software Foundation Apache ActiveMQ 5.19.12, 6.3.3
  • Apache Software Foundation Apache ActiveMQ KahaDB 5.19.12, 6.3.3

Is CVE-2026-111821 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-111821 updated cvss 6.5

org.apache.activemq/activemq-kahadb-store: activemq-kahadb-store: Denial of Service via oversized durable subscription identifiers

  • Red Hat Fuse 7 activemq-kahadb-store 5.11.0.redhat-630517
    affected: no fix planned “Out of support scope”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-09).

Affected products

  • Apache Software Foundation Apache ActiveMQ
  • Apache Software Foundation Apache ActiveMQ KahaDB

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

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