Jenkins 2.270 through 2.393 (both inclusive), LTS 2.277.1 through 2.375.3 (both inclusive) does not escape the Jenkins version a plugin depends on when rendering the error message stating its incompatibility with the current version of Jenkins, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers able to provide plugins to the configured update sites and have this message shown by Jenkins instances.