CVE-2026-48087 OpenReception: WebAuthn passkey injection allows account takeover
An attacker can inject their own WebAuthn passkey into a victim's account by manipulating the user ID during registration, leading to account takeover.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-48087?
CVE-2026-48087 is a critical authentication bypass vulnerability in open-reception appointment-booking-software, published on 6 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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 to authenticated tenant members per the route signature; live verification of all exposure surfaces (whether user IDs leak through any unauthenticated route, through invite-confirmation URLs, or through other administrative views) is part of the pending live PoC. Where the attacker knows the victim's email and userId, the analysis below becomes account takeover. Version 1.0.2 fixes the issue.
Weakness: CWE-287
Which versions are affected by CVE-2026-48087?
How do I fix CVE-2026-48087?
No fix has been published for CVE-2026-48087 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-48087 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-48087 exists.
Sources
Also known as GHSA-j9rw-x2wv-h5rj.