Rocket.Chat is an open-source, secure, fully customizable communications platform. Prior to 8.5.0, 8.4.2, 8.3.4, 8.2.4, 8.1.5, 8.0.6, 7.13.8, and 7.10.12, Rocket.Chat does not revoke OAuth bearer or refresh tokens when a user is deactivated. A deactivated user can continue using an existing OAuth access token, and can also mint a fresh access token from an existing refresh token. This vulnerability is fixed in 8.5.0, 8.4.2, 8.3.4, 8.2.4, 8.1.5, 8.0.6, 7.13.8, and 7.10.12.