CVE-2026-39304Denial of Service via Out of Memory vulnerability in Apache ActiveMQ Client, Apache ActiveMQ Broker, Apache ActiveMQ.
Updated under an hour ago ()
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Denial of Service via Out of Memory vulnerability in Apache ActiveMQ Client, Apache ActiveMQ Broker, Apache ActiveMQ. ActiveMQ NIO SSL transports do not correctly handle TLSv1.3 handshake KeyUpdates triggered by clients. This makes it possible for a client to rapidly trigger updates which causes the broker to exhaust all its memory in the SSL engine leading to DoS. Note: TLS versions before TLSv1.3 (such as TLSv1.2) are broken but are not vulnerable to OOM. Previous TLS versions require a full handshake renegotiation which causes a connection to hang but not OOM. This is fixed as well. This issue affects Apache ActiveMQ Client: before 5.19.4, from 6.0.0 before 6.2.4; Apache ActiveMQ Broker: before 5.19.4, from 6.0.0 before 6.2.4; Apache ActiveMQ: before 5.19.4, from 6.0.0 before 6.2.4. Users are recommended to upgrade to version 6.2.4 or 5.19.5, which fixes the issue.
- CVSS
- 7.5 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-400, CWE-770
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Modified
- Record last updated
- Jul 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
apache activemq apache:activemq | before 5.19.4; from 6.0.0 before 6.2.4 | NVD |
apache activemq_broker apache:activemq_broker | before 5.19.4; from 6.0.0 before 6.2.4 | NVD |
References
- https://activemq.apache.org/security-advisories.data/CVE-2026-39304-announcement.txtvendor-advisory
- http://www.openwall.com/lists/oss-security/2026/04/09/17mailing-list, third-party-advisory
- https://access.redhat.com/security/cve/CVE-2026-39304
- https://bugzilla.redhat.com/show_bug.cgi?id=2457275
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39304.json
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.