GHSA-gq2m-77hf-vwgh: OliveTin Session Fixation: Logout Fails to Invalidate Server-Side Session

OliveTin does not revoke server-side sessions when a user logs out. Although the browser cookie is cleared, the corresponding session remains valid in server storage until expiry (default ≈ 1 year).

An attacker with a previously stolen or captured session cookie can continue authenticating after logout, resulting in a post-logout authentication bypass.

This is a session management flaw that violates expected logout semantics.