{"id":"CVE-2021-33604","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-33604","generatedAt":"2026-10-28T05:26:28.538Z","title":"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…","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.","published":"2021-06-24T12:15:08.000Z","lastModified":"2026-06-17T03:54:52.000Z","status":"Modified","sourceIdentifier":"security@vaadin.com","cvss":{"version":"3.1","score":2.5,"severity":"LOW","vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N"},"cwe":["CWE-172"],"affected":["vaadin/flow-server","vaadin/vaadin"],"epss":{"score":0.00286,"percentile":0.20963,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.29%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/vaadin/flow/pull/11099","tags":["Patch","Third Party Advisory"],"source":"security@vaadin.com"},{"url":"https://vaadin.com/security/cve-2021-33604","tags":["Vendor Advisory"],"source":"security@vaadin.com"},{"url":"https://github.com/vaadin/flow/pull/11099","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://vaadin.com/security/cve-2021-33604","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-33604","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}