{"id":"CVE-2021-39140","aliases":["GHSA-6wf9-jmg9-vxcc"],"url":"https://o3.security/vulnerability/CVE-2021-39140","summary":"XStream can cause a Denial of Service","details":"XStream is a simple library to serialize objects to XML and back again. In affected versions this vulnerability 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. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types. XStream 1.4.18 uses no longer a blacklist by default, since it cannot be secured for general purpose.","published":"2021-08-23T19:15:10.440Z","modified":"2026-07-08T06:27:13.980370663Z","cvss":{"score":6.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H"},"epss":{"score":0.05918,"percentile":0.92749,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"Maven","name":"com.thoughtworks.xstream:xstream","fixedVersion":"1.4.18"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/x-stream/xstream/security/advisories/GHSA-6wf9-jmg9-vxcc"},{"type":"ADVISORY","url":"https://lists.debian.org/debian-lts-announce/2021/09/msg00017.html"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20210923-0003/"},{"type":"ADVISORY","url":"https://www.debian.org/security/2021/dsa-5004"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpuapr2022.html"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpujan2022.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/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP/"},{"type":"ARTICLE","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7/"},{"type":"ARTICLE","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB/"},{"type":"EVIDENCE","url":"https://x-stream.github.io/CVE-2021-39140.html"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-08T06:27:13.980370663Z"}}