Laravel TokenGuard authentication bypass through non-string API credentials

Laravel's built-in TokenGuard, when configured with a standard token-based API guard, may be bypassed to authenticate as an arbitrary existing user without knowledge of their valid API token.

Under certain database configurations (MySQL/MariaDB) an attacker can submit a specially crafted, non-string credential value that is mishandled during the authentication lookup, causing the underlying query to match an unintended user record rather than failing authentication as expected.

Impact

An unauthenticated attacker may authenticate as another user without possessing that user's API token, leading to authentication bypass and account takeover on any route protected by the affected guard.