{"cve":"CVE-2021-21610","nvd":{"published":"2021-01-13T16:15:14.007","modified":"2026-06-17T03:35:52.140","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1},"cwes":["CWE-79"],"references":["https://www.jenkins.io/security/advisory/2021-01-13/#SECURITY-2153","https://www.jenkins.io/security/advisory/2021-01-13/#SECURITY-2153"],"products":["jenkins:jenkins"],"source":"nvd","synced_at":"2026-10-19T21:14:10.479542811+00:00"},"epss":{"cve":"CVE-2021-21610","score":0.01199,"percentile":0.68162,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-7qf3-c2q8-69m3","url":"https://osv.dev/vulnerability/GHSA-7qf3-c2q8-69m3","summary":"Reflected XSS vulnerability in Jenkins markup formatter preview","modified":"2024-02-16T07:55:46.670061Z","packages":[{"ecosystem":"Maven","name":"org.jenkins-ci.main:jenkins-core","purl":"pkg:maven/org.jenkins-ci.main/jenkins-core","ranges":["<2.263.2"],"fixed":["2.263.2"]},{"ecosystem":"Maven","name":"org.jenkins-ci.main:jenkins-core","purl":"pkg:maven/org.jenkins-ci.main/jenkins-core","ranges":[">=2.264 <2.275"],"fixed":["2.275"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}