Jenkins 2.213 and earlier, LTS 2.204.1 and earlier improperly reuses encryption key parameters in the Inbound TCP Agent Protocol/3, allowing unauthorized attackers with knowledge of agent names to obtain the connection secrets for those agents, which can be used to connect to Jenkins, impersonating those agents.
Jenkins 2.218 and earlier, LTS 2.204.1 and earlier did not use a constant-time comparison function for validating connection secrets, which could potentially allow an attacker to use a timing attack to obtain this secret.
In Jenkins 2.196 and earlier, LTS 2.176.3 and earlier, the f:expandableTextBox form control interpreted its content as HTML when expanded, resulting in a stored XSS vulnerability exploitable by users with permission to define its contents (typically Job/Configure).
In Jenkins 2.196 and earlier, LTS 2.176.3 and earlier, the f:combobox form control interpreted its item labels as HTML, resulting in a stored XSS vulnerability exploitable by users with permission to define its contents.
Jenkins 2.196 and earlier, LTS 2.176.3 and earlier did not escape the SCM tag name on the tooltip for SCM tag actions, resulting in a stored XSS vulnerability exploitable by users able to control SCM tag names for these actions.