{"id":"CVE-2021-21610","aliases":["BIT-jenkins-2021-21610","GHSA-7qf3-c2q8-69m3"],"url":"https://o3.security/vulnerability/CVE-2021-21610","summary":"Reflected XSS vulnerability in Jenkins markup formatter preview","details":"Jenkins 2.274 and earlier, LTS 2.263.1 and earlier does not implement any restrictions for the URL rendering a formatted preview of markup passed as a query parameter, resulting in a reflected cross-site scripting (XSS) vulnerability if the configured markup formatter does not prohibit unsafe elements (JavaScript) in markup.","published":"2021-01-13T16:15:14.007Z","modified":"2026-07-08T21:25:43.501865Z","cvss":{"score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"org.jenkins-ci.main:jenkins-core","fixedVersion":"2.263.2"},{"ecosystem":"Maven","name":"org.jenkins-ci.main:jenkins-core","fixedVersion":"2.275"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://www.jenkins.io/security/advisory/2021-01-13/#SECURITY-2153"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-08T21:25:43.501865Z"}}