Vulnerability Description
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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Apache | Activemq | >= 5.16.0, < 5.16.8 |
Related Weaknesses (CWE)
References
- https://lists.apache.org/thread/8hcm25vf7mchg4zbbhnlx2lc5bs705hgMailing ListVendor Advisory
- http://www.openwall.com/lists/oss-security/2025/05/06/1Mailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2025/06/msg00020.html
FAQ
What is CVE-2025-27533?
CVE-2025-27533 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 excess...
How severe is CVE-2025-27533?
CVE-2025-27533 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-27533?
Check the references section above for vendor advisories and patch information. Affected products include: Apache Activemq.