Vulnerability in Apache Activemq
CVE-2026-50734
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.007 (52.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 52.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000
Affected products
- Apache Activemq
- Apache Software Foundation Activemq — versions 0, 6.0.0
- Apache Software Foundation Activemq All — versions 0, 6.0.0
- Apache Software Foundation Activemq Client — versions 0, 6.0.0
Weakness classification (CWE)
References
- lists.apache.org/thread/nxso951fnvf72qf9m475mpz4yf931xk0 (vendor-advisory, Mailing List, Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Third Party Advisory)
Frequently asked questions
- What is CVE-2026-50734?
- CVE-2026-50734 is a high-severity vulnerability in Apache Activemq, classified under CWE-789. CVSS score: 7.5/10. Published 2026-06-30.
- How severe is CVE-2026-50734?
- High severity. CVSS v3 base score is 7.5 out of 10.