NVD / CVE Program· CNA apache

CVE-2026-39304: Apache ActiveMQ Client, Apache ActiveMQ Broker, Apache ActiveMQ All, Apache ActiveMQ: Incorrect handling of TLSv1.3 KeyUpdate can be exploited to cause DoS via

Noroxi assessment

Priority: Monitor (action score 30/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.91% (FIRST EPSS); higher than 60.2% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: Apache Software Foundation Apache ActiveMQ 5.19.4, 6.2.4; Apache Software Foundation Apache ActiveMQ All 5.19.4, 6.2.4; Apache Software Foundation Apache ActiveMQ Broker 5.19.4, 6.2.4.

Low priority for now. Upgrade to Apache Software Foundation Apache ActiveMQ 5.19.4, 6.2.4; Apache Software Foundation Apache ActiveMQ All 5.19.4, 6.2.4; Apache Software Foundation Apache ActiveMQ Broker 5.19.4, 6.2.4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.5 · v3.1—No exploit Fix available

Published: Apr 10, 2026
Updated: Oct 26, 2026
EPSS: 0.9% · 60th percentile
CWE: CWE-400

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.9%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
apache	activemq	cpe:2.3:a:apache:activemq
apache	activemq broker	cpe:2.3:a:apache:activemq_broker

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

apache activemqbefore 5.19.4
apache activemq6.0.0 and later · before 6.2.4
apache activemq brokerbefore 5.19.4
apache activemq broker6.0.0 and later · before 6.2.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

Apache Software Foundation Apache ActiveMQ
- before 5.19.4affected · semver
- 6.0.0 and later · before 6.2.4affected · semver
Apache Software Foundation Apache ActiveMQ All
- before 5.19.4affected · semver
- 6.0.0 and later · before 6.2.4affected · semver
Apache Software Foundation Apache ActiveMQ Broker
- before 5.19.4affected · semver
- 6.0.0 and later · before 6.2.4affected · semver
Apache Software Foundation Apache ActiveMQ Client
- before 5.19.4affected · semver
- 6.0.0 and later · before 6.2.4affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	activemq	from 0	—
Maven	org.apache.activemq:activemq-all	from 6.0.0 · before 6.2.4	6.2.4
Maven	org.apache.activemq:activemq-all	before 5.19.4	5.19.4
Maven	org.apache.activemq:activemq-broker	from 6.0.0 · before 6.2.4	6.2.4
Maven	org.apache.activemq:activemq-broker	before 5.19.4	5.19.4
Maven	org.apache.activemq:activemq-client	from 6.0.0 · before 6.2.4	6.2.4
Maven	org.apache.activemq:activemq-client	before 5.19.4	5.19.4
Maven	org.apache.activemq:apache-activemq	from 6.0.0 · before 6.2.4	6.2.4
Maven	org.apache.activemq:apache-activemq	before 5.19.4	5.19.4

Same product

apache: all records

Other highest-scoring records for the same primary product.

CVE-2023-46604Apache ActiveMQ, Apache ActiveMQ Legacy OpenWire Module: Unbounded deserialization causes ActiveMQ to be vulnerable to a remote code execution (RCE) attackKEV
99Now
CVE-2016-3088The Fileserver web application in Apache ActiveMQ 5.x before 5.14.0 allows remote attackers to upload and execute arbitrary files via an HTTKEV
99Now
CVE-2026-34197Apache ActiveMQ Broker, Apache ActiveMQ All, Apache ActiveMQ: Authenticated users could perform RCE via Jolokia MBeansKEV
94Now

Published before and after this one in the same product

← EarlierCVE-2025-66168Mar 4, 2026 · Apache ActiveMQ, Apache ActiveMQ All Module, Apache ActiveMQ MQTT Module: MQTT control packet remaining length field is not properly validated
35Monitor
← EarlierCVE-2026-33227Apr 7, 2026 · Apache ActiveMQ Client, Apache ActiveMQ Broker, Apache ActiveMQ All, Apache ActiveMQ Web, Apache ActiveMQ: Improper Limitation of a Pathname to a Restricted Cla
17Monitor
Later →CVE-2026-40466Apr 24, 2026 · Apache ActiveMQ Broker, Apache ActiveMQ All, Apache ActiveMQ: Possible bypass of CVE-2026-34197 via HTTP discovery second-stage URI
36Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Apache Software Foundation Apache ActiveMQ	5.19.4	Vendor (CNA)
Apache Software Foundation Apache ActiveMQ	6.2.4	Vendor (CNA)
Apache Software Foundation Apache ActiveMQ All	5.19.4	Vendor (CNA)
Apache Software Foundation Apache ActiveMQ All	6.2.4	Vendor (CNA)
Apache Software Foundation Apache ActiveMQ Broker	5.19.4	Vendor (CNA)
Apache Software Foundation Apache ActiveMQ Broker	6.2.4	Vendor (CNA)
Apache Software Foundation Apache ActiveMQ Client	5.19.4	Vendor (CNA)
Apache Software Foundation Apache ActiveMQ Client	6.2.4	Vendor (CNA)
Maven:org.apache.activemq:activemq-all	5.19.4	Package registry (OSV)
Maven:org.apache.activemq:activemq-all	6.2.4	Package registry (OSV)
Maven:org.apache.activemq:activemq-broker	5.19.4	Package registry (OSV)
Maven:org.apache.activemq:activemq-broker	6.2.4	Package registry (OSV)
Maven:org.apache.activemq:activemq-client	5.19.4	Package registry (OSV)
Maven:org.apache.activemq:activemq-client	6.2.4	Package registry (OSV)
Maven:org.apache.activemq:apache-activemq	5.19.4	Package registry (OSV)
Maven:org.apache.activemq:apache-activemq	6.2.4	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-5075081 days apartApache ActiveMQ Broker, Apache ActiveMQ, Apache ActiveMQ All: Pre-authentication OpenWire DoS following fix for CVE-2026-49270
30Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: none
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: None
Availability impact: High

Weakness class (CWE)

CWE-400 · Uncontrolled Resource Consumption

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-secondary

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

The bug in code

The whole CWE-400 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1function expand(node) {
2  return node.children.map(expand);
3}

Fixed

1const MAX_DEPTH = 32;
2function expand(node, depth = 0) {
3  if (depth > MAX_DEPTH) throw new Error("too deep");
4  return node.children.map((c) => expand(c, depth + 1));
5}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Endpoint Denial of ServiceT1499

Change log

Fix✗ → ✓Sep 28, 2026, 10:08 PM UTC

For records you follow, these changes also arrive as notifications. →

References

activemq.apache.org/security-advisories.data/CVE-2026-39304-announcement.txt

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records