CVE-2023-37895: Java object deserialization issue in Jackrabbit webapp/standalone on all platforms allows attacker to remotely execute code via RMIVersions up to (including) 2.

Java object deserialization issue in Jackrabbit webapp/standalone on all platforms allows attacker to remotely execute code via RMIVersions up to (including) 2.

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 recommend to disable RMI access altogether (see further below), and will discuss deprecating RMI support in future Jackrabbit releases. How to check whether RMI support is enabledRMI support can be over an RMI-specific TCP port, and over an HTTP binding. Both are by default enabled in Jackrabbit webapp/standalone. The native RMI protocol by default uses port 1099. To check whether it is enabled,

Description from the National Vulnerability Database, published by security@apache.org

What it means for a small business

Apache Jackrabbit Webapp (jackrabbit-webapp) runs on web servers, so this is mostly your hosting company's to fix. On shared hosting you can't patch it yourself, but you can ask.

Ask your host whether your server runs it, whether it's updated, and on what date. A good host answers that in a day.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 3.2%, higher than 88% of CVEs. That’s above average: worth scheduling this week. Scored October 28, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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