In the Samly package before 1.4.0 for Elixir, Samly.State.Store.get_assertion/3 can return an expired session, which interferes with access control because Samly.AuthHandler uses a cached session and does not replace it, even after expiry.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:HI:HA:N9.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N