Apache ActiveMQ Improper Input Validation
CVE-2026-34197 is a high-severity improper input validation vulnerability in Apache ActiveMQ Broker from Apache, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions 5.19.4, 6.2.3 as the first without the flaw, so updating Apache ActiveMQ Broker to one of those releases or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on April 16, 2026, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update Apache ActiveMQ Broker to 5.19.4 or 6.2.3, whichever matches your release line, or a later version.
- Update Apache ActiveMQ All to 5.19.4 or 6.2.3, whichever matches your release line, or a later version.
- Update Apache ActiveMQ to 5.19.4 or 6.2.3, whichever matches your release line, or a later version.
- CISA's 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.
- Read the advisory on activemq.apache.org for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apache | Apache ActiveMQ Broker | before 5.19.4; 6.0.0 up to, but not including, 6.2.3 | 5.19.4, 6.2.3 |
| Apache | Apache ActiveMQ All | before 5.19.4; 6.0.0 up to, but not including, 6.2.3 | 5.19.4, 6.2.3 |
| Apache | Apache ActiveMQ | before 5.19.4; 6.0.0 up to, but not including, 6.2.3 | 5.19.4, 6.2.3 |
| Red Hat | Red Hat AMQ Broker 7 | Not specified in the record | Not stated |
| Red Hat | Red Hat Data Grid 8 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9 | Not specified in the record | Not stated |
| Red Hat | Red Hat Fuse 7 | Not specified in the record | Not stated |
| Red Hat | Red Hat JBoss Enterprise Application Platform 7 | Not specified in the record | Not stated |
| Red Hat | Red Hat JBoss Enterprise Application Platform 8 | Not specified in the record | Not stated |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | Not specified in the record | Not stated |
| Apache | Activemq | before 5.19.4; 6.0.0 up to, but not including, 6.2.3 | 5.19.4, 6.2.3 |
| Apache | Activemq Broker | before 5.19.4; 6.0.0 up to, but not including, 6.2.3 | 5.19.4, 6.2.3 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | CISA (ADP) |
| CVSS 3.1 | 8.8 | High | CNA |
Official 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
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: 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.
How developers prevent this class of flaw
- Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
- Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
Timeline
- CVE record published.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- openwall.com/lists/oss-security/2026/04/06/3Mailing List, Third Party Advisory
- access.redhat.com/security/cve/CVE-2026-34197Third Party Advisory
- bugzilla.redhat.com/show_bug.cgi?id=2455869Third Party Advisory
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34197.jsonThird Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-34197US Government Resource
Other vulnerabilities in Apache ActiveMQ Broker
- 7.5 High severity
- 7.5 High severity
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- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
Recent Improper Input Validation vulnerabilities
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