CVE detail
CVE-2026-39304
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.
Buzz score
Why this CVE is surfacing
This all-time snapshot uses the same composite formula as Trending across a 30-year evidence window, rather than a current rolling window.
Buzz score components · mention 17.9 · diversity 14.5 · KEV 0.0 · OTX 0.0 · PoC 0.0
Why it matters now
Mention timeline
- Total mentions
- 0
- within the 30d window
- Peak daily
- 0
- highest bucket
Evidence
Source links by recency
5 source links · newest first
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39304.jsonsecurity.access.redhat.com
No excerpt available.
Vendor Advisorysecurity.access.redhat.comApr 10, 2026, 11:16 AM - https://bugzilla.redhat.com/show_bug.cgi?id=2457275bugzilla.redhat.com
No excerpt available.
Exploitbugzilla.redhat.comApr 10, 2026, 11:16 AM - https://access.redhat.com/security/cve/CVE-2026-39304access.redhat.com
No excerpt available.
Vendor Advisoryaccess.redhat.comApr 10, 2026, 11:16 AM - http://www.openwall.com/lists/oss-security/2026/04/09/17www.openwall.com
No excerpt available.
Exploitwww.openwall.comApr 10, 2026, 11:16 AM - https://activemq.apache.org/security-advisories.data/CVE-2026-39304-announcement.txtactivemq.apache.org
No excerpt available.
Vendor Advisoryactivemq.apache.orgApr 10, 2026, 11:16 AM
Exploit code
Public exploit repository references
Public PoC repositories are third-party, potentially unsafe artifacts. Treat their code as untrusted and use it only on authorized systems in an isolated, least-privilege environment. cvebuzz does not execute the code or verify that an exploit works.
0 repository references · best confidence N/A · max 0 stars
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