Review reviewHigh

CVE-2026-53917

Apache Software Foundation Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ Client

Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ Client, Apache ActiveMQ Broker. An authenticated user can cause a broker DoS by sending a crafted OpenWire Message with a large encoded size value for the map. OpenWire message property maps are unmarshaled without size validation which can trigger OOM and crash the broker. This issue affects Apache ActiveMQ: before 5.19.8, from 6.0.0 before 6.2.7; Apache ActiveMQ All: before 5.19.8, from 6.0.0 before 6.2.7; Apache ActiveMQ Client: before 5.19.8, from 6.0.0 before 6.2.7; Apache...

CVSS: 7.5
EPSS: 1.18%
CISA KEV: Not listed
Published: 2026.06.30

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability1.18%

Technical severityCVSS 7.5

Vulnerability overview

Affected product and versions

Product: Apache Software Foundation Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ Client
Affected versions: 6.0.0, < 5.19.8, >= 6.0.0 < 6.2.7
Fixed versions: 5.19.8, 6.2.7

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Apache Software Foundation Apache ActiveMQ, Apache ActiveMQ All, Apache ActiveMQ Client and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE: CWE-789