CVE-2026-66909: Apache CXF: Unsafe deserialization of inbound JMS ObjectMessage

[Colm O hEigeartaigh <coheigea () apache org>]

Severity: important 

Affected versions:

- Apache CXF (org.apache.cxf:cxf-rt-transports-jms) 4.2.0 before 4.2.3
- Apache CXF (org.apache.cxf:cxf-rt-transports-jms) 4.0.0 before 4.1.8
- Apache CXF (org.apache.cxf:cxf-rt-transports-jms) before 3.6.12

Description:

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.

Credit:

Reported by n0mi1k (finder)

References:

https://cxf.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-66909