Vulnerability · Published Jun 30, 2026 · Assigned by apache
CVE-2026-50734Apache ActiveMQ Client, Apache ActiveMQ, Apache ActiveMQ All: Pre-authentication OpenWire memory-allocation DoS during wire format negotiation
High 7.5
In plain English
A high-severity security flaw in Apache ActiveMQ from Apache Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 55% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Memory Allocation with Excessive Size Value vulnerability in Apache ActiveMQ Client, Apache ActiveMQ, Apache ActiveMQ All. An unauthenticated network attacker can cause a broker DoS by sending a crafted WireFormatInfo frame with a malicious large size value. The value is not validate and causes the broker to attempt allocation during pre-auth negotiation which can trigger OOM and crash the broker. This issue affects Apache ActiveMQ Client: before 5.19.8, from 6.0.0 before 6.2.7; 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. Users are recommended to upgrade to version 6.2.7 or 5.19.8, which fixes the issue.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | activemq | no fix listed | DEBIAN-CVE-2026-50734 |
| Debian:13 | activemq | no fix listed | DEBIAN-CVE-2026-50734 |
| Maven | org.apache.activemq:activemq-all | 5.19.8 | GHSA-7259-vf48-52q3 |
| Maven | org.apache.activemq:activemq-all | 6.2.7 | GHSA-7259-vf48-52q3 |
| Maven | org.apache.activemq:activemq-client | 5.19.8 | GHSA-7259-vf48-52q3 |
| Maven | org.apache.activemq:activemq-client | 6.2.7 | GHSA-7259-vf48-52q3 |
| Maven | org.apache.activemq:apache-activemq | 6.2.7 | GHSA-7259-vf48-52q3 |
| Maven | org.apache.activemq:apache-activemq | 5.19.8 | GHSA-7259-vf48-52q3 |
| Ubuntu:24.04:LTS | activemq | no fix listed | UBUNTU-CVE-2026-50734 |
| Ubuntu:25.10 | activemq | no fix listed | UBUNTU-CVE-2026-50734 |
| Ubuntu:26.04:LTS | activemq | no fix listed | UBUNTU-CVE-2026-50734 |
| Ubuntu:26.10 | activemq | no fix listed | UBUNTU-CVE-2026-50734 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Apache Software Foundation | Apache ActiveMQ Client | 0 – before 5.19.86.0.0 – before 6.2.7 |
| Apache Software Foundation | Apache ActiveMQ | 0 – before 5.19.86.0.0 – before 6.2.7 |
| Apache Software Foundation | Apache ActiveMQ All | 0 – before 5.19.86.0.0 – before 6.2.7 |
Weakness: CWE-789 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H