CVE-2026-84652 [HIGH] – In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, Jenkins does not rotate the session

In Jenkins 2.579 and earlier, LTS 2.568.2 and earlier, Jenkins does not rotate the session when a user is authenticated via the “remember me” cookie, allowing attackers able to serve content on the same site as Jenkins to set a known session cookie in the victim’s browser, which after the victim authenticates via the “remember me” cookie, grants the attacker access to Jenkins as that user.