Critical Vulnerabilities in Apache ActiveMQ Demand Immediate Patching
Apache ActiveMQ users must apply urgent security updates following the disclosure of two critical vulnerabilities CVE-2026-42253 and CVE-2026-49157 that expose systems to HTTP header injection and privilege escalation risks.
CVE-2026-42253: HTTP Response Header Injection via JMS Properties
Affected versions of Apache ActiveMQ and its web components (prior to 5.19.7 and 6.2.6) contain a flaw in the MessageServlet component, where JMS message properties are unsafely copied into HTTP response headers without validation. This allows attackers to inject or manipulate headers, including Content-Security-Policy, Set-Cookie, and Access-Control-Allow-Origin, leading to potential cross-site scripting (XSS), session hijacking, cache poisoning, or security control bypasses. The vulnerability is exploitable in environments where the web console is exposed, particularly in loosely secured messaging setups.
CVE-2026-49157: Improper Jolokia Authorization
The second flaw affects the Jolokia management interface, where default authorization settings are overly permissive. Authenticated low-privilege users can retain access to administrative operations, such as modifying queues, enabling unauthorized configuration changes or messaging disruptions. This issue also impacts versions before 5.19.7 and 6.2.6.
Impact and Mitigation
Both vulnerabilities are rated "important" by the Apache Software Foundation. Exploitation could result in security control bypasses, privilege escalation, or infrastructure abuse. Apache has addressed the issues by disabling the vulnerable MessageServlet by default in patched releases (5.19.7 and 6.2.6). Security researchers Vishal Shukla, pyn3rd, uname, 4ra1n, and Leon Johnson were credited with discovering the flaws, underscoring risks in default configurations and input validation.
Organizations using affected versions should upgrade immediately, restrict management interface access, and audit JMS message flows to mitigate exposure.
Source: https://gbhackers.com/critical-activemq-vulnerability/
Apache Software Foundation TPRM report: https://www.rankiteo.com/company/the-apache-software-foundation
"id": "the1780489477",
"linkid": "the-apache-software-foundation",
"type": "Vulnerability",
"date": "6/2026",
"severity": "85",
"impact": "4",
"explanation": "Attack with significant impact with customers data leaks"{'affected_entities': [{'industry': 'Technology/Software',
'name': 'Apache ActiveMQ',
'type': 'Software'}],
'attack_vector': ['Exposed web console', 'Jolokia management interface'],
'description': 'Apache ActiveMQ users must apply urgent security updates '
'following the disclosure of two critical vulnerabilities '
'CVE-2026-42253 and CVE-2026-49157 that expose systems to HTTP '
'header injection and privilege escalation risks. '
'CVE-2026-42253 allows HTTP response header injection via JMS '
'properties, leading to potential XSS, session hijacking, '
'cache poisoning, or security control bypasses. CVE-2026-49157 '
'involves improper Jolokia authorization, enabling '
'unauthorized configuration changes or messaging disruptions.',
'impact': {'operational_impact': ['Security control bypasses',
'Messaging disruptions',
'Unauthorized configuration changes'],
'systems_affected': 'Apache ActiveMQ versions prior to 5.19.7 and '
'6.2.6'},
'lessons_learned': 'Risks in default configurations and input validation can '
'lead to critical vulnerabilities. Regular audits and '
'immediate patching are essential.',
'post_incident_analysis': {'corrective_actions': ['Disable vulnerable '
'MessageServlet by default',
'Tighten Jolokia '
'authorization settings'],
'root_causes': ['Unsafe copying of JMS message '
'properties into HTTP headers',
'Overly permissive default '
'authorization settings in '
'Jolokia']},
'recommendations': ['Upgrade to Apache ActiveMQ versions 5.19.7 or 6.2.6 '
'immediately',
'Restrict access to management interfaces',
'Audit JMS message flows for potential injection risks'],
'references': [{'source': 'Apache Software Foundation'}],
'response': {'containment_measures': ['Upgrade to patched versions (5.19.7 or '
'6.2.6)',
'Disable vulnerable MessageServlet by '
'default'],
'remediation_measures': ['Restrict management interface access',
'Audit JMS message flows']},
'title': 'Critical Vulnerabilities in Apache ActiveMQ Demand Immediate '
'Patching',
'type': ['Vulnerability Disclosure',
'Privilege Escalation',
'HTTP Header Injection'],
'vulnerability_exploited': ['CVE-2026-42253', 'CVE-2026-49157']}