Java object deserialization issue in Jackrabbit webapp/standalone on all platforms allows attacker to remotely execute code via RMIVersions up to (including) 2.20.10 (stable branch) and 2.21.17 (unstable branch) use the component "commons-beanutils", which contains a class that can be used for remote code execution over RMI. Users are advised to immediately update to versions 2.20.11 or 2.21.18. Note that earlier stable branches (1.0.x .. 2.18.x) have been EOLd already and do not receive updates anymore. In general, RMI support can expose vulnerabilities by the mere presence of an exploitable class on the classpath. Even if Jackrabbit itself does not contain any code known to be exploitable anymore, adding other components to your server can expose the same type of problem. We therefore