Vulnerabilities

Logto allows unverified email-based SSO account linking, enabling an attacker to register an identity at a permissive IdP using a victim’s email and gain unauthorized access to the victim’s account.

Logto bypasses OIDC nonce validation when the nonce claim is absent from the id_token, enabling replay of authentication tokens and weakening session-binding.

Logto silently fails to delete IdP-initiated SAML sessions, enabling session replay and reuse within the session’s validity window.

Logto omits validation of the SAML <Conditions> element, enabling attackers to strip time and audience restrictions and replay assertions indefinitely.

Logto does not enforce locally configured MFA during SSO authentication, allowing users to bypass second-factor requirements and grants unauthorized access.

Logto performs principal lookup without normalizing email and identifier strings, enabling principal collision and unauthorized account access via case- or Unicode-different identities.