{"id":"CVE-2021-31406","aliases":["GHSA-p7jq-v8jp-j424"],"url":"https://o3.security/vulnerability/CVE-2021-31406","summary":"Timing side channel vulnerability in endpoint request handler in Vaadin 15-19","details":"Non-constant-time comparison of CSRF tokens in endpoint request handler in com.vaadin:flow-server versions 3.0.0 through 5.0.3 (Vaadin 15.0.0 through 18.0.6), and com.vaadin:fusion-endpoint version 6.0.0 (Vaadin 19.0.0) allows attacker to guess a security token for Fusion endpoints via timing attack.","published":"2021-04-23T16:15:08.727Z","modified":"2026-08-07T16:50:25.522658Z","cvss":{"score":2.5,"severity":"LOW","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Maven","name":"com.vaadin:flow-server","fixedVersion":"5.0.4"},{"ecosystem":"Maven","name":"com.vaadin:flow-server","fixedVersion":"6.0.1"}],"fix":{"url":"https://github.com/vaadin/flow/pull/10157","label":"vaadin/flow#10157"},"references":[{"type":"ADVISORY","url":"https://vaadin.com/security/cve-2021-31406"},{"type":"FIX","url":"https://github.com/vaadin/flow/pull/10157"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T16:50:25.522658Z"}}