CVE-2026-34197

Apache ActiveMQ Improper Input Validation Vulnerability

Actively exploited (CISA KEV) High 8.8 CVSS 3.1

Description

Improper Input Validation, Improper Control of Generation of Code ('Code Injection') vulnerability in Apache ActiveMQ Broker, Apache ActiveMQ. Apache ActiveMQ Classic exposes the Jolokia JMX-HTTP bridge at /api/jolokia/ on the web console. The default Jolokia access policy permits exec operations on all ActiveMQ MBeans (org.apache.activemq:*), including BrokerService.addNetworkConnector(String) and BrokerService.addConnector(String). An authenticated attacker can invoke these operations with a crafted discovery URI that triggers the VM transport's brokerConfig parameter to load a remote Spring XML application context using ResourceXmlApplicationContext. Because Spring's ResourceXmlApplicationContext instantiates all singleton beans before the BrokerService validates the configuration, arbitrary code execution occurs on the broker's JVM through bean factory methods such as Runtime.exec(). This issue affects Apache ActiveMQ Broker: before 5.19.4, from 6.0.0 before 6.2.3; Apache ActiveMQ All: before 5.19.4, from 6.0.0 before 6.2.3; Apache ActiveMQ: before 5.19.4, from 6.0.0 before 6.2.3. Users are recommended to upgrade to version 5.19.4 or 6.2.3, which fixes the issue

Description as published by the source, in English.

Key facts

Published: 2026-04-07
Last modified: 2026-08-04
Assigned by: security@apache.org
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Scored by: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Probability of exploitation: 97.2 % among the highest of all known vulnerabilities
EPSS, next 30 days, model v2026.06.15
Fix available: Not registered in the sources

Actively exploited

CISA added this vulnerability to the Known Exploited Vulnerabilities catalogue on 2026-04-16, with a remediation deadline of 2026-04-30 for US federal agencies.

Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Affected products

Vendor	Product	Versions	Status
Apache	Activemq	< 5.19.4	Affected
Apache	Activemq	≥ 6.0.0, < 6.2.3	Affected
Apache	Activemq Broker	< 5.19.4	Affected
Apache	Activemq Broker	≥ 6.0.0, < 6.2.3	Affected

Weakness type

CWE-20: Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS …
CWE-94: Improper Control of Generation of Code ('Code Injection')
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or b…

Attack techniques

Derived through the weakness type: CVE to CWE to CAPEC to ATT&CK. This shows which techniques the weakness class is historically used for. It does not assert that this vulnerability has been exploited that way.

T1027: Obfuscated Files or Information stealth
T1027.006: HTML Smuggling stealth
T1027.009: Embedded Payloads stealth
T1036.001: Invalid Code Signature stealth
T1539: Steal Web Session Cookie credential-access
T1553.002: Code Signing defense-impairment
T1564.009: Resource Forking stealth
T1574.006: Dynamic Linker Hijacking stealth, execution
T1574.007: Path Interception by PATH Environment Variable stealth, execution

References

https://activemq.apache.org/security-advisories.data/CVE-2026-34197-announcement.txt Vendor Advisory
http://www.openwall.com/lists/oss-security/2026/04/06/3 Mailing List, Third Party Advisory
https://access.redhat.com/security/cve/CVE-2026-34197 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2455869 Third Party Advisory
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34197.json Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-34197 US Government Resource

Related at Berigo

Articles

New ActiveMQ flaw bypasses the fix for an actively exploited bug Mentions this CVE 2026-04-24
CVE-2026-40466 in Apache ActiveMQ bypasses the fix for CVE-2026-34197, a flaw reported as already under active exploitation.
Critical code execution flaw found in Apache ActiveMQ Classic Mentions this CVE 2026-04-07
CVE-2026-34197 sits in the Jolokia API and lets an attacker run arbitrary commands. Upgrading and removing default credentials is advised.
Attackers are exploiting the plug-in in front of Oracle WebLogic Same product 2026-08-25
CISA added CVE-2026-21962 to its Known Exploited Vulnerabilities Catalog on 24 August, citing evidence of active exploitation. The flaw sits in Oracl…
The crypto library behind Python now ships quantum-resistant algorithms Same product 2026-08-18
Trail of Bits has added ML-KEM and ML-DSA to pyca/cryptography, funded by the Sovereign Tech Agency. The library is the eleventh most downloaded pack…

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Sources and freshness

CVE

What it is: A reference number naming one specific vulnerability, for example CVE-2024-9474.
What it tells you: Which vulnerability we are talking about, and in which product.
What it does NOT tell you: Nothing about how serious it is, whether anyone is exploiting it, or whether it concerns you.
Why it matters: Without a shared number, vendor, authority and tooling cannot discuss the same flaw.
Used with the others: The number is the key. NVD, KEV and EPSS all describe the same CVE.

NVD CWE CISA KEV EPSS

How to read this together

No single value should be used on its own. A high CVSS score does not mean a vulnerability is being exploited, and a low one does not mean it is harmless. The four sources answer four different questions.

CVE names the specific vulnerability.
NVD adds severity and technical detail about it.
CWE describes the type of mistake behind it.
CISA KEV shows that it is already being exploited.
EPSS estimates how likely exploitation is soon.

The order that decides what is urgent

Do you actually have the product?
Is the version you run affected?
Is it listed in CISA KEV?
Does it have a high EPSS score?
Is the system reachable from the internet or from others?
How important is the system to the business?
Are there compensating controls already in place?

The first two questions are not about the vulnerability at all. They are about you, and they remove most of the list before you start.

A short example

Fix this week

CVSS 6,5 (medium)

In CISA KEV: yes
EPSS: 94 per cent
A firewall facing the internet

Can be scheduled

CVSS 9,8 (critical)

In CISA KEV: no
EPSS: 0,04 per cent
A test server with no internet access

Sorted by CVSS alone, the one on the right comes first. It is the more serious flaw in theory. But the one on the left is being used against real organisations right now, and it sits where an attacker can reach it. That is the one to fix first.

The critical one still has to be fixed. It just does not have to be fixed today.

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