In Jenkins 2.355 and earlier, LTS 2.332.3 and earlier, an observable timing discrepancy on the login form allows distinguishing between login attempts with an invalid username, and login attempts with a valid username and wrong password, when using the Jenkins user database security realm.
Add your gear to cvedb and we'll alert you only when jenkins ships something exploited.
Check my exposure →This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.