{"id":"CVE-2021-43859","aliases":["BIT-jenkins-2021-43859","GHSA-rmr5-cpv2-vgjf"],"url":"https://o3.security/vulnerability/CVE-2021-43859","summary":"Denial of Service by injecting highly recursive collections or maps in XStream","details":"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.","published":"2022-02-01T12:15:08.080Z","modified":"2026-07-09T11:34:47.102078Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":2,"affectedPackages":[{"ecosystem":"Maven","name":"com.thoughtworks.xstream:xstream","fixedVersion":"1.4.19"}],"fix":{"url":"https://github.com/x-stream/xstream/commit/e8e88621ba1c85ac3b8620337dd672e0c0c3a846","label":"x-stream/xstream@e8e8862"},"references":[{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2024/12/msg00023.html"},{"type":"ADVISORY","url":"http://www.openwall.com/lists/oss-security/2022/02/09/1"},{"type":"ADVISORY","url":"https://lists.debian.org/debian-lts-announce/2022/02/msg00018.html"},{"type":"FIX","url":"https://github.com/x-stream/xstream/commit/e8e88621ba1c85ac3b8620337dd672e0c0c3a846"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpuapr2022.html"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpujul2022.html"},{"type":"ARTICLE","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VACQYG356OHUTD5WQGAQ4L2TTFTAV3SJ/"},{"type":"ARTICLE","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XODFRE2ZL64FICBJDOPWOLPTSSAI4U7X/"},{"type":"EVIDENCE","url":"https://github.com/x-stream/xstream/security/advisories/GHSA-rmr5-cpv2-vgjf"},{"type":"EVIDENCE","url":"https://x-stream.github.io/CVE-2021-43859.html"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T11:34:47.102078Z"}}