Apache Tapestry 3.x allows deserialization of untrusted data, leading to remote code execution. This issue is similar to but distinct from CVE-2020-17531, which applies the the (also unsupported) 4.x version line. NOTE: This vulnerability only affects Apache Tapestry version line 3.x, which is no longer supported by the maintainer. Users are recommended to upgrade to a supported version line of Apache Tapestry.