Enonic XP versions less than 7.7.4 are vulnerable to a session fixation issue. An remote and unauthenticated attacker can use prior sessions due to the lack of invalidating session attributes.
https://vulncheck.com/advisories/vc-advisory-GHSA-4m5p-5w5w-3jcf
https://github.com/enonic/xp/security/advisories/GHSA-4m5p-5w5w-3jcf