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Fencer Intel
high —

CVE-2026-108946 json

Apache ActiveMQ, ActiveMQ Broker: The broker does not verify user provided connection id matches connection

published 5d ago modified 5d ago also EUVD-2026-116828

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 13%
public exploits
0
none known

Summary

Improper input validation vulnerability in Apache ActiveMQ, Apache ActiveMQ KahaDB.

The ActiveMQ broker resolves connection, session and consumer state from ids that are user provided and in some scenarios does not validate that they ids are bound to that user. This allows an authenticated client to spoof another user's ids. This allows:

*  an authenticated client consumes from another connection's temporary queue/topic by putting the victim's connection id in its own ConsumerId, bypassing the broker-side ownership check.  * a duplicate ConsumerId registration is only logged, after which the attacker's RemoveInfo or disconnect tears down the victim's live subscription * a forged MessageAck for the victim's ConsumerId permanently deletes an in-flight, unacknowledged message.

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 ActiveMQ Broker 5.19.12, 6.3.3

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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-2026-108946 updated cvss 6.3

org.apache.activemq/activemq-broker: org.apache.activemq/activemq-kahadb-store: ActiveMQ: unauthorized message access via user identifier spoofing

  • Red Hat Fuse 7 activemq-broker 5.11.0.redhat-630517, 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

0.23% chance of exploitation in the next 30 days, higher than 13% of all scored CVEs (FIRST EPSS, 2026-11-09).

Affected products

  • Apache Software Foundation Apache ActiveMQ
  • Apache Software Foundation ActiveMQ Broker

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.