anonhaven
Ad

CVE-2026-39304

HIGH CVSS 3.1: 7.5 EPSS 0.02%
Updated Apr 10, 2026
Apache
Parameter Value
CVSS 7.5 (HIGH)
Affected Versions before 5.19.4
Fixed In 6.2.4
Type CWE-400 (Uncontrolled Resource Consumption)
Vendor Apache
Public PoC No

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.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service

CVSS Vector v3.1

Weakness Type (CWE)

CWE-400 Uncontrolled Resource Consumption

References 2

https://activemq.apache.org/security-advisories.data/CVE-2026-39304-announcemen…
security@apache.org
http://www.openwall.com/lists/oss-security/2026/04/09/17
af854a3a-2127-422b-91ae-364da2661108
Share Post Share Share Share

Related Vulnerabilities

CVE-2026-30778

Apache

7.5

CVE-2026-5088

Apache

7.5

CVE-2026-33929

Apache

4.3

CVE-2026-33704

Apache

8.8

CVE-2026-40023

Apache

6.3