CVE-2026-43866

HIGHCVSS 7.3/10EPSS 0.18%

Last modified

CVE-2026-43866 is a high-severity vulnerability rated 7.3/10 on the CVSS scale. 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.**;!*. EPSS estimates a 0.18% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
7.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

EPSS Probability
0.18%

7.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
Apache Software FoundationApache Camel>= 3.0.0, < 4.14.8; >= 4.15.0, < 4.18.3; >= 4.19.0, < 4.21.0

References

Timeline

Published
Last Modified
Status
Undergoing Analysis

Frequently Asked Questions

What is CVE-2026-43866?
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.
How severe is CVE-2026-43866?
CVE-2026-43866 has a CVSS score of 7.3/10 (HIGH severity). The EPSS model estimates a 0.18% probability of exploitation in the next 30 days.
How do I fix CVE-2026-43866?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST