CVE-2026-48087

Technical Description

OpenReception's appointment booking software provides an end-to-end encrypted appointment booking platform. Prior to version 1.0.2, the registration handler at `POST /api/auth/register/{userId}` validates the relationship between the WebAuthn challenge and the registration cookie's email but never validates that the `userId` in the URL belongs to that email. An unauthenticated attacker requests a challenge for their own email, generates a registration response with their own authenticator, and submits it against any victim user's URL. The challenge-vs-cookie email match passes, the WebAuthn ceremony validates, and `addPasskey` writes the attacker's credential into the victim's `user_passkey` rows. The next victim-email login accepts a passkey assertion from the attacker's authenticator and issues a session as the victim. User IDs are not strictly secret on this platform, but the exact set of exposure surfaces should be assessed by the maintainers. Staff-list endpoints return user IDs t

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References