Mastodon is a free, open-source social network server based on ActivityPub. In Mastodon before 4.4.6, 4.3.14, and 4.2.27, when an administrator resets a user accounts password via the command-line interface using bin/tootctl accounts modify --reset-password, active sessions and access tokens for that account are not revoked. This allows an attacker with access to a previously compromised session or token to continue using the account after the password has been reset. This issue has been patched in versions 4.2.27, 4.3.14, and 4.4.6. No known workarounds exist.
According to WASC, “Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization.”