Summary
Apache Camel JMS deserialization filter bypass
Deserialization of Untrusted Data vulnerability in Apache Camel, Apache Camel JMS component.
JmsBinding.extractBodyFromJms() in camel-jms - and the equivalent JmsBinding in camel-sjms - deserializes the payload of an incoming JMS ObjectMessage via jakarta.jms.ObjectMessage.getObject() whenever the mapJmsMessage option is enabled (the default) and Camel acts as a JMS consumer. The CVE-2026-40860 hardening added a post-deserialization class check that rejects classes outside the default allow-list java.;javax.;org.apache.camel.;!*. However org.apache.camel.support.DefaultExchangeHolder itself lives in the allow-listed org.apache.camel. namespace, so an ObjectMessage whose top-level object is a DefaultExchangeHolder passes the check. The receiving side then calls DefaultExchangeHolder.unmarshal() on it without requiring the transferExchange option to be enabled - an asymmetric trust boundary, since the sending side gates ObjectMessage and transferExchange handling but the receiving side did not - writing every non-null field of the holder into the Exchange: the message body, the IN and OUT headers, the exchange properties, the variables, the exchange id and the exception. An attacker who can publish an ObjectMessage to a queue or topic consumed by an affected Camel application can therefore inject arbitrary Exchange state using only universally-trusted java.lang and java.util types, with no deserialization gadget chain required, to manipulate routing and headers, exchange properties and error handling. The same handling applies to camel-sjms and camel-sjms2, and to the JMS-family components built on JmsComponent and JmsBinding: camel-amqp, camel-activemq and camel-activemq6. This is a bypass of the CVE-2026-40860 fix rather than a flaw in it.
This issue affects Apache Camel: from 3.0.0 before 4.14.8, from 4.15.0 before 4.18.3, from 4.19.0 before 4.21.0; Apache Camel: from 3.0.0 before 4.14.8, from 4.15.0 before 4.18.3, from 4.19.0 before 4.21.0.
Users are recommended to upgrade to version 4.21.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.8. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.3. After upgrading, JMS ObjectMessage handling is disabled by default in camel-jms, camel-sjms and the JMS-family components (a new objectMessageEnabled option defaults to false at the component and endpoint level), so an incoming ObjectMessage - including a DefaultExchangeHolder payload - is no longer deserialized unless the option is explicitly enabled; only set objectMessageEnabled=true when the consumed JMS destination is fed exclusively by trusted producers. For deployments that cannot upgrade immediately, restrict publish access to the queues and topics consumed by Camel to trusted producers via JMS broker authorization, and do not expose JMS consumers that map ObjectMessage bodies to untrusted networks; a JMS-provider deserialization allow-list does not mitigate this specific bypass because the crafted payload uses only universally-trusted classes.
Impact
Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect. Typical impact: arbitrary code execution or logic abuse.
CVE-2026-43866 has a CVSS score of 7.3 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (4.14.8, 4.18.3, 4.21.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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org.apache.camel:camel-jms to 4.14.8 or later; org.apache.camel:camel-jms to 4.18.3 or later; org.apache.camel:camel-jms to 4.21.0 or later; org.apache.camel:camel-sjms to 4.14.8 or later; org.apache.camel:camel-sjms to 4.18.3 or later; org.apache.camel:camel-sjms to 4.21.0 or later; org.apache.camel:camel-sjms2 to 4.14.8 or later; org.apache.camel:camel-sjms2 to 4.18.3 or later; org.apache.camel:camel-sjms2 to 4.21.0 or later; org.apache.camel:camel-amqp to 4.14.8 or later; org.apache.camel:camel-amqp to 4.18.3 or later; org.apache.camel:camel-amqp to 4.21.0 or later; org.apache.camel:camel-activemq to 4.14.8 or later; org.apache.camel:camel-activemq to 4.18.3 or later; org.apache.camel:camel-activemq to 4.21.0 or later; org.apache.camel:camel-activemq6 to 4.14.8 or later; org.apache.camel:camel-activemq6 to 4.18.3 or later; org.apache.camel:camel-activemq6 to 4.21.0 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-43866? CVE-2026-43866 is a high-severity insecure deserialization vulnerability in org.apache.camel:camel-jms (maven), affecting versions >= 3.0.0, < 4.14.8. It is fixed in 4.14.8, 4.18.3, 4.21.0. Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect.
- How severe is CVE-2026-43866? CVE-2026-43866 has a CVSS score of 7.3 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which packages are affected by CVE-2026-43866?
org.apache.camel:camel-jms(maven) (versions >= 3.0.0, < 4.14.8)org.apache.camel:camel-sjms(maven) (versions >= 3.0.0, < 4.14.8)org.apache.camel:camel-sjms2(maven) (versions >= 3.0.0, < 4.14.8)org.apache.camel:camel-amqp(maven) (versions >= 3.0.0, < 4.14.8)org.apache.camel:camel-activemq(maven) (versions >= 3.0.0, < 4.14.8)org.apache.camel:camel-activemq6(maven) (versions >= 3.0.0, < 4.14.8)
- Is there a fix for CVE-2026-43866? Yes. CVE-2026-43866 is fixed in 4.14.8, 4.18.3, 4.21.0. Upgrade to this version or later.
- Is CVE-2026-43866 exploitable, and should I be worried? Whether CVE-2026-43866 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-43866 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-43866?
- Upgrade
org.apache.camel:camel-jmsto 4.14.8 or later - Upgrade
org.apache.camel:camel-jmsto 4.18.3 or later - Upgrade
org.apache.camel:camel-jmsto 4.21.0 or later - Upgrade
org.apache.camel:camel-sjmsto 4.14.8 or later - Upgrade
org.apache.camel:camel-sjmsto 4.18.3 or later - Upgrade
org.apache.camel:camel-sjmsto 4.21.0 or later - Upgrade
org.apache.camel:camel-sjms2to 4.14.8 or later - Upgrade
org.apache.camel:camel-sjms2to 4.18.3 or later - Upgrade
org.apache.camel:camel-sjms2to 4.21.0 or later - Upgrade
org.apache.camel:camel-amqpto 4.14.8 or later - Upgrade
org.apache.camel:camel-amqpto 4.18.3 or later - Upgrade
org.apache.camel:camel-amqpto 4.21.0 or later - Upgrade
org.apache.camel:camel-activemqto 4.14.8 or later - Upgrade
org.apache.camel:camel-activemqto 4.18.3 or later - Upgrade
org.apache.camel:camel-activemqto 4.21.0 or later - Upgrade
org.apache.camel:camel-activemq6to 4.14.8 or later - Upgrade
org.apache.camel:camel-activemq6to 4.18.3 or later - Upgrade
org.apache.camel:camel-activemq6to 4.21.0 or later
- Upgrade