# CVE-2025-27533: Apache ActiveMQ: Unchecked buffer length can cause excessive memory allocation

Source: https://junglewise.ai/threats/cve-2025-27533-apache-activemq-unchecked-buffer-length-can-cause-excessive  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-05-07  
License: CC BY 4.0 with a link back

CVE-2025-27533 · Severity: low · CVSS 3.1 · Published 2025-05-07

Apache ActiveMQ: Unchecked buffer length can cause excessive memory allocation

Technologies: [org.apache.activemq:activemq-client (Maven)](https://junglewise.ai/threats/technologies/org-apache-activemq-activemq-client). Vendors: [Maven](https://junglewise.ai/threats/vendors/maven).

## Quick answers

**Is CVE-2025-27533 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-27533 being exploited in the wild.

**How severe is CVE-2025-27533?** Low severity, with a CVSS score of 3.1, published 7 May 2025.

**Which products and versions are affected?** org.apache.activemq:activemq-client (Maven) ECOSYSTEM:introduced=0,fixed=5.16.8; org.apache.activemq:activemq-openwire-legacy (Maven) ECOSYSTEM:introduced=0,fixed=5.16.8.

**Is there a fix for CVE-2025-27533?** Yes. org.apache.activemq:activemq-client (Maven): upgrade to 5.16.8 or later; org.apache.activemq:activemq-openwire-legacy (Maven): upgrade to 5.16.8 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2025-27533?** Check whether you run org.apache.activemq:activemq-client (Maven) or org.apache.activemq:activemq-openwire-legacy (Maven) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- org.apache.activemq:activemq-client (Maven): upgrade to 5.16.8 or later

  ```sh
  # set org.apache.activemq:activemq-client to 5.16.8 in your pom.xml or build.gradle
  ```

- org.apache.activemq:activemq-openwire-legacy (Maven): upgrade to 5.16.8 or later

  ```sh
  # set org.apache.activemq:activemq-openwire-legacy to 5.16.8 in your pom.xml or build.gradle
  ```


## Affected products

- org.apache.activemq:activemq-client (Maven) ECOSYSTEM:introduced=0,fixed=5.16.8
- org.apache.activemq:activemq-openwire-legacy (Maven) ECOSYSTEM:introduced=0,fixed=5.16.8

## Identifiers

- CVE-2025-27533
- GHSA-whxr-3p84-rf3c

## Related threats

- [Apache ActiveMQ DoS via excessive memory allocation in OpenWire map unmarshaling](https://junglewise.ai/threats/cve-2026-53917-apache-activemq-dos-via-excessive-memory-allocation-in-openwire)
- [Apache ActiveMQ denial of service via excessive memory allocation](https://junglewise.ai/threats/cve-2026-50734-apache-activemq-denial-of-service-via-excessive-memory-allocation)
- [Apache ActiveMQ DoS via memory exhaustion in NIO SSL transport](https://junglewise.ai/threats/cve-2026-39304-apache-activemq-dos-via-memory-exhaustion-in-nio-ssl-transport)
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- [Armatura One multiple vulnerabilities in access control system](https://junglewise.ai/threats/cve-2023-46604-apache-activemq-deserialization-of-untrusted-data-vulnerability)