Apache ActiveMQ: Unchecked buffer length can cause excessive memory allocation
Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ.
During unmarshalling of OpenWire commands the size value of buffers was not properly validated which could lead to excessive memory allocation and be exploited to cause a denial of service (DoS) by depleting process memory, thereby affecting applications and services that rely on the availability of the ActiveMQ broker when not using mutual TLS connections. This issue affects Apache ActiveMQ: from 6.0.0 before 6.1.6, from 5.18.0 before 5.18.7, from 5.17.0 before 5.17.7, before 5.16.8. ActiveMQ 5.19.0 is not affected.
Users are recommended to upgrade to version 6.1.6+, 5.19.0+, 5.18.7+, 5.17.7, or 5.16.8 or which fixes the issue.
Existing users may implement mutual TLS to mitigate the risk on affected brokers.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | org.apache.activemq:activemq-client | < 5.16.8, >= 5.17.0, < 5.17.7, >= 5.18.0, < 5.18.7, >= 6.0.0, < 6.1.6 | 5.16.8, 5.17.7, 5.18.7, 6.1.6 |
| Java / Kotlin (Maven) | org.apache.activemq:activemq-openwire-legacy | < 5.16.8, >= 5.17.0, < 5.17.7, >= 5.18.0, < 5.18.7, >= 6.0.0, < 6.1.6 | 5.16.8, 5.17.7, 5.18.7, 6.1.6 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2025-27533
- https://github.com/apache/activemq/commit/fc4372b9f0f72b8b5eed917f0019c5cea45c5d06
- https://github.com/apache/activemq
- https://issues.apache.org/jira/browse/AMQ-6596
- https://lists.apache.org/thread/8hcm25vf7mchg4zbbhnlx2lc5bs705hg
- https://lists.debian.org/debian-lts-announce/2025/06/msg00020.html
- http://www.openwall.com/lists/oss-security/2025/05/06/1
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness (CWE)
CWE-789- Platform
- Java / Kotlin (Maven)
- Package
org.apache.activemq:activemq-client, org.apache.activemq:activemq-openwire-legacy- Disclosed
- 07.05.2025
- Updated
- 11.10.2026 13:20
Sources and licenses
OSV / GitHub Advisory Database - GHSA-whxr-3p84-rf3c - CC BY 4.0
Vulnerability history: org.apache.activemq:activemq-client
All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 18
- First → latest
- 10.2018 04.2026
- Without a fix
- 0
- Exploited in attacks
- 2
Severity breakdown
- Critical 4
- High 4
- Medium 10
Disclosures per year
- 2018: 1
- 2019: 2
- 2020: 0
- 2021: 0
- 2022: 11
- 2023: 1
- 2024: 0
- 2025: 1
- 2026: 2
-
Apache ActiveMQ: Unchecked buffer length can cause excessive memory allocation this entry
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