{"cve":"CVE-2021-33604","nvd":{"published":"2021-06-24T12:15:08.157","modified":"2026-06-17T03:54:51.847","status":"Modified","description":"URL encoding error in development mode handler in com.vaadin:flow-server versions 2.0.0 through 2.6.1 (Vaadin 14.0.0 through 14.6.1), 3.0.0 through 6.0.9 (Vaadin 15.0.0 through 19.0.8) allows local user to execute arbitrary JavaScript code by opening crafted URL in browser.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N","score":2.5},"cwes":["CWE-172"],"references":["https://github.com/vaadin/flow/pull/11099","https://vaadin.com/security/cve-2021-33604","https://github.com/vaadin/flow/pull/11099","https://vaadin.com/security/cve-2021-33604"],"products":["vaadin:flow-server","vaadin:vaadin"],"source":"nvd","synced_at":"2026-10-19T21:20:07.141963181+00:00"},"epss":{"cve":"CVE-2021-33604","score":0.00286,"percentile":0.21132,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-c99r-67x4-whj6","url":"https://osv.dev/vulnerability/GHSA-c99r-67x4-whj6","summary":"Reflected cross-site scripting in development mode handler in Vaadin 14, 15-19","modified":"2024-02-17T05:31:46.930420Z","packages":[{"ecosystem":"Maven","name":"com.vaadin:vaadin-bom","purl":"pkg:maven/com.vaadin/vaadin-bom","ranges":[">=14.0.0 <14.6.2"],"fixed":["14.6.2"]},{"ecosystem":"Maven","name":"com.vaadin:vaadin-bom","purl":"pkg:maven/com.vaadin/vaadin-bom","ranges":[">=15.0.0 <19.0.9"],"fixed":["19.0.9"]}]}],"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."]}