Detect Apache ActiveMQ Improper Input Validation (CVE-2026-34197) in Splunk
Detects exploitation of CVE-2026-34197, an improper input validation vulnerability (CWE-20/CWE-94) in Apache ActiveMQ that has been added to the CISA Known Exploited Vulnerabilities catalog. Successful exploitation may allow remote attackers to execute arbitrary code or inject malicious content via crafted messages or broker connections. ActiveMQ's OpenWire protocol and web console are common attack surfaces for this class of vulnerability.
MITRE ATT&CK
- Tactic
- Initial Access Execution Persistence
SPL Detection Query
index=* sourcetype IN ("cisco:asa", "pan:traffic", "stream:tcp", "xmlwf", "syslog", "WinEventLog:Security", "XmlWinEventLog:Microsoft-Windows-Sysmon/Operational")
| eval activemq_port=if(dest_port IN (61616, 61617, 8161, 8162, 5672, 1883, 61613) OR src_port IN (61616, 61617, 8161, 8162, 5672, 1883, 61613), 1, 0)
| eval suspicious_cmd=if(match(CommandLine, "(?i)(classinfo|ClassPathXmlApplicationContext|ExceptionResponse|cmd\.exe|/bin/sh|powershell|wget|curl|base64|ncat|/tmp/)"), 1, 0)
| eval suspicious_proc=if(match(ParentImage, "(?i)(activemq|java)") AND suspicious_cmd=1, 1, 0)
| where activemq_port=1 OR suspicious_proc=1
| eval attack_vector=case(suspicious_proc=1, "process_spawn", activemq_port=1 AND suspicious_cmd=1, "network_payload", activemq_port=1, "port_contact", true(), "unknown")
| stats count AS event_count, values(attack_vector) AS attack_vectors, min(_time) AS first_seen, max(_time) AS last_seen, values(dest_ip) AS dest_ips, values(CommandLine) AS command_lines BY src_ip, host
| where event_count >= 1
| eval severity="critical"
| sort -event_countDetects CVE-2026-34197 exploitation attempts in Apache ActiveMQ by identifying anomalous connections to ActiveMQ service ports combined with suspicious child process spawning from Java/ActiveMQ parent processes.
Data Sources
Required Sourcetypes
False Positives & Tuning
- Legitimate administrative connections to ActiveMQ broker ports from authorized management hosts
- Automated monitoring scripts that spawn child processes from the ActiveMQ service account
- Java application servers co-located with ActiveMQ that naturally communicate on these ports
- Security scanning tools performing authorized vulnerability assessments against ActiveMQ
Other platforms for CVE-2026-34197
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1ActiveMQ OpenWire Port Probe with Malicious Payload Pattern
Expected signal: Network connection event to port 61616 from non-standard source; payload content containing 'ClassPathXmlApplicationContext' visible in network capture or IDS alerts
- Test 2Simulated Post-Exploitation Shell Spawn from Java Process
Expected signal: Sysmon Event ID 1 or Linux audit execve showing bash/sh spawned with parent process containing 'java' in the image path; process command line containing 'id', 'hostname', or 'whoami'
- Test 3ActiveMQ Web Console Access with Path Traversal Attempt
Expected signal: HTTP access log entries on port 8161 containing '../' path sequences and 'ClassPathXmlApplicationContext' in request body or destination parameter; network connection events to port 8161 from unexpected source
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