CVE-2026-50734: Apache ActiveMQ denial of service via excessive memory allocation

CVE-2026-50734 · Severity: high · CVSS 7.5 · Published 2026-06-30

Apache ActiveMQ is a popular open-source message broker used to facilitate communication between different software applications. A vulnerability in how it handles initial connection requests allows an unauthenticated attacker to crash the service by forcing it to exhaust its available memory. This results in a denial-of-service (DoS) condition, disrupting message delivery and business operations that rely on the broker.

Technologies: Apache Software Foundation ActiveMQ All, Apache Software Foundation ActiveMQ Client, org.apache.activemq:activemq-all (Maven), org.apache.activemq:activemq-client (Maven), org.apache.activemq:apache-activemq (Maven). Vendors: Apache Software Foundation, Maven.

Quick answers

Is CVE-2026-50734 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-50734 being exploited in the wild.
How severe is CVE-2026-50734?
High severity, with a CVSS score of 7.5, published 30 June 2026.
Which products and versions are affected?
Apache Software Foundation ActiveMQ All before 5.19.8, 6.0.0 to 6.2.6; Apache Software Foundation ActiveMQ Client before 5.19.8, 6.0.0 to 6.2.6; org.apache.activemq:activemq-all (Maven) < 5.19.8, ECOSYSTEM:introduced=0,fixed=5.19.8; org.apache.activemq:activemq-client (Maven) < 5.19.8, ECOSYSTEM:introduced=0,fixed=5.19.8; and 1 more.
Is there a fix for CVE-2026-50734?
Yes. org.apache.activemq:activemq-all (Maven): upgrade to 5.19.8 or later; org.apache.activemq:activemq-client (Maven): upgrade to 5.19.8 or later; org.apache.activemq:apache-activemq (Maven): upgrade to 5.19.8 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-50734 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-50734?
Check whether you run Apache Software Foundation ActiveMQ All, Apache Software Foundation ActiveMQ Client, org.apache.activemq:activemq-all (Maven) or one of the others listed 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-all (Maven): upgrade to 5.19.8 or later
    # set org.apache.activemq:activemq-all to 5.19.8 in your pom.xml or build.gradle
  • org.apache.activemq:activemq-client (Maven): upgrade to 5.19.8 or later
    # set org.apache.activemq:activemq-client to 5.19.8 in your pom.xml or build.gradle
  • org.apache.activemq:apache-activemq (Maven): upgrade to 5.19.8 or later
    # set org.apache.activemq:apache-activemq to 5.19.8 in your pom.xml or build.gradle

Technical details

A Memory Allocation with Excessive Size Value vulnerability (CWE-789) exists in the Apache ActiveMQ broker. The flaw is located in the handling of WireFormatInfo frames during the pre-authentication negotiation phase. An unauthenticated remote attacker can send a crafted frame containing a malicious, large size value that the broker fails to validate. This causes the broker to attempt a massive memory allocation, leading to an Out-of-Memory (OOM) error and a subsequent process crash. The issue is resolved in versions 5.19.8 and 6.2.7.

Affected products

  • Apache ActiveMQ Client before 5.19.8, 6.0.0 to 6.2.6
  • Apache ActiveMQ before 5.19.8, 6.0.0 to 6.2.6
  • Apache ActiveMQ All before 5.19.8, 6.0.0 to 6.2.6

Identifiers

  • CVE-2026-50734
  • BIT-ACTIVEMQ-2026-50734
  • GHSA-7259-vf48-52q3

Timeline

  • 2026-06-30: disclosed
  • 2026-06-30: advisory

References

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