GHSA-26c5-ppr8-f33p Synapse has improper checks for deactivated users during login

• PyPI matrix-synapse: < 1.85.0 → fixed in 1.85.0

Impact It may be possible for a deactivated user to login when using uncommon configurations. This only applies if any of the following are true: • JSON Web Tokens are enabled for login via the `jwt_config.enabled` configuration setting • The local password database is enabled via the `password_config.enabled` and `password_config.localdb_enabled` configuration settings *and* a user's password is updated via an admin API after a user is deactivated. Note that the local password database is enabled by default, but it is uncommon to set a user's password after they've been deactivated. Installations that are configured to only allow login via Single Sign-On (SSO) via CAS, SAML or OpenID Connect (OIDC); or via an external password provider (e.g. LDAP) are not affected. Patches • If using JSON Web Token logins: #15624 • For other users: #15634 Workarounds If not using JSON Web Tokens, ensure that deactivated users do not have a password set. This list of users can be queried from PostgreSQL: ```sql SELECT name FROM users WHERE password_hash IS NOT NULL AND deactivated = 1; ```