CVE-2026-18056 Auth bypass in HivePress Authentication
Unauthenticated attackers can bypass authentication and log in as any user, including administrators, by supplying a valid Facebook access token without proper validation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-18056?
CVE-2026-18056 is a high-severity authentication bypass vulnerability in HivePress Authentication, published on 6 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
The HivePress Authentication plugin for WordPress is vulnerable to Authentication Bypass via the access_token parameter in all versions up to, and including, 1.1.4. This is due to the authenticate_user function's Facebook authenticator resolving third-party identity by forwarding the attacker-supplied access_token to the Facebook Graph API and trusting the returned email and ID verbatim, without performing any application ID or audience validation — specifically, no /debug_token verification and no comparison of the token's app_id against the configured hp_facebook_app_id. This makes it possible for unauthenticated attackers to authenticate as any existing WordPress user, including administrators, whose email address is associated with a Facebook account for which the attacker can obtain any valid access token. Important Note: To exploit the vulnerability, the attacker must obtain the victim's access token.
Weakness: CWE-287
Which versions are affected by CVE-2026-18056?
How do I fix CVE-2026-18056?
No fix has been published for CVE-2026-18056 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-2026-18056 being exploited?
There is no known exploitation of CVE-2026-18056 in the wild and no public exploit code.
Sources
Also known as GHSA-55w6-5hh5-wj3r.