XStream is an open source java library to serialize objects to XML and back again. Versions prior to 1.4.19 may allow a remote attacker to allocate 100% CPU time on the target system depending on CPU type or parallel execution of such a payload resulting in a denial of service only by manipulating the processed input stream. XStream 1.4.19 monitors and accumulates the time it takes to add elements to collections and throws an exception if a set threshold is exceeded. Users are advised to upgrade as soon as possible. Users unable to upgrade may set the NO_REFERENCE mode to prevent recursion. See GHSA-rmr5-cpv2-vgjf for further details on a workaround if an upgrade is not possible.
https://x-stream.github.io/CVE-2021-43859.html
https://www.oracle.com/security-alerts/cpujul2022.html
https://www.oracle.com/security-alerts/cpuapr2022.html
https://lists.debian.org/debian-lts-announce/2022/02/msg00018.html
https://github.com/x-stream/xstream/security/advisories/GHSA-rmr5-cpv2-vgjf
https://github.com/x-stream/xstream/commit/e8e88621ba1c85ac3b8620337dd672e0c0c3a846