What’s Vulnerable › Vulnerabilities

CVE-2026-86404: Artemis-server: artemis-jms-client: artemis-core-client: undertow-core: wildfly-messaging-activemq-subsystem: artemis messaging handlers in red hat eap permit deserialization by default

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-07 · updated 2026-11-01
• Weakness: CWE-502

Description

EAP's Artemis deserialization configuration permits deserialization by default. ObjectMessage.getObject() uses ObjectInputStreamWithClassLoader, which implements allow-list/block-list filtering via its checkSecurity()/isTrustedType() method. However, by default both allow-list and block-list are empty. When the allow-list is empty (size == 0), isTrustedType() returns true for ALL classes. This means all classes are deserializable by default.

Affected products

• Red Hat JBoss Enterprise Application Platform 7: all versions
• Red Hat JBoss Enterprise Application Platform 8: all versions
• Red Hat JBoss Enterprise Application Platform 8.1.8.GA: all versions — fixed in 2.40.0.redhat-00024
• Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 10: all versions — fixed in 0:2.40.0-8.redhat_00024.1.el10eap
• Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8: all versions — fixed in 0:2.40.0-8.redhat_00024.1.el8eap
• Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9: all versions — fixed in 0:2.40.0-8.redhat_00024.1.el9eap

How to fix

Upgrade to a fixed version: Red Hat JBoss Enterprise Application Platform 8.1.8.GA 2.40.0.redhat-00024; Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 10 0:2.40.0-8.redhat_00024.1.el10eap; Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8 0:2.40.0-8.redhat_00024.1.el8eap; Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9 0:2.40.0-8.redhat_00024.1.el9eap. Check the vendor advisory for mitigations.

References

• https://access.redhat.com/errata/RHSA-2026:70228
• https://access.redhat.com/errata/RHSA-2026:70229
• https://access.redhat.com/errata/RHSA-2026:70230
• https://access.redhat.com/errata/RHSA-2026:70277
• https://access.redhat.com/security/cve/CVE-2026-86404
• https://bugzilla.redhat.com/show_bug.cgi?id=2477930

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