Mattermost versions 9.11.X <= 9.11.1, 9.5.x <= 9.5.9 icorrectly issues two sessions when using desktop SSO - one in the browser and one in desktop with incorrect settings.
Exploitability
AV:NAC:LPR:LUI:RScope
S:UImpact
C:LI:NA:N3.5/CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:NOther