CVE-2026-66909: Apache Cxf

Critical severity, CVSS 9.8. EPSS: 1.1% chance of exploitation in the next 30 days.

Apache CXF's JMS transport deserializes the body of any inbound JMS ObjectMessage using native Java deserialization, with no type restrictions in place. Any attacker able to place a message on the service's JMS destination can submit a malicious serialized object, leading to denial of service or, if a suitable gadget class is on the classpath, remote code execution. The fix disables ObjectMessage deserialization by default, with a configuration switch to re-enable it if needed. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fix this issue.

Affected products

• Apache Cxf: before 3.6.12 (fixed in 3.6.12); from 4.0.0, before 4.1.8 (fixed in 4.1.8); from 4.2.0, before 4.2.3 (fixed in 4.2.3)

Published 2026-08-06. Last modified 2026-08-07.