CVE-2026-39304
HIGHCVSS v3.1: 7.5 · EPSS: 0.0068 (47.9 percentile)
Source data as of:
At a glance
- Severity
- HIGH
- CVSS
- 7.5 v3.1 · NVD
- EPSS
- 0.0068 (47.9 percentile) · FIRST.org
- CISA KEV
- No
- Type
- Resource Exhaustion (DoS), Resource Exhaustion · NVD CWE
- Attack conditions (CVSS vector)
- NetworkNo privilegesNo user interaction · Source: NVD Vector
- Affected vendors
- apache
- Published
- 2026-04-10 · Modified: 2026-06-30
- References
- Jump to references (5)
CVSS / EPSS / KEV
Source — CVSS: NVD · EPSS: FIRST.org · KEV: CISA. Data & Sources
Description
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.
References
Reference URLs as listed by NVD, grouped by a mechanical match on the link's host/pattern. Labels describe the link type only.
- Vendor advisory https://activemq.apache.org/security-advisories.data/CVE-2026-39304-announcement.txt
- Reference http://www.openwall.com/lists/oss-security/2026/04/09/17
- Distro https://access.redhat.com/security/cve/CVE-2026-39304
- Distro https://bugzilla.redhat.com/show_bug.cgi?id=2457275
- Distro https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39304.json