CVE-2026-50734
Apache ActiveMQ Client, Apache ActiveMQ, Apache ActiveMQ All: Pre-authentication OpenWire memory-allocation DoS during wire format negotiation
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.
How to fix CVE-2026-50734
To remediate CVE-2026-50734, upgrade the affected package to a fixed version below.
- —upgrade to 5.19.8 or later
Is CVE-2026-50734 being exploited?
Low — EPSS is 0.8%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 5.19.8, >= 6.0.0, < 6.2.7
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |