CVE-2026-2991

CVE-2026-2991 is a high-severity vulnerability with a CVSS 3.x base score of 7.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Description

The KiviCare – Clinic & Patient Management System (EHR) plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 4.1.2. This is due to the `patientSocialLogin()` function not verifying the social provider access token before authenticating a user. This makes it possible for unauthenticated attackers to log in as any patient registered on the system by providing only their email address and an arbitrary value for the access token, bypassing all credential verification. The attacker gains access to sensitive medical records, appointments, prescriptions, and billing information (PII/PHI breach). Additionally, authentication cookies are set before the role check, meaning the auth cookies for non-patient users (including administrators) are also set in the HTTP response headers, even though a 403 response is returned.

Frequently asked questions

What is CVE-2026-2991?
The KiviCare – Clinic & Patient Management System (EHR) plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 4.1.2. This is due to the `patientSocialLogin()` function not verifying the social provider access token before authenticating a user. This makes it possible for unauthenticated attackers to log in as any patient registered on the system by providing only their email address and an arbitrary value for the access token, bypassing all credential verification. The attacker gains access to sensitive medical records, appointments, prescriptions, and billing information (PII/PHI breach). Additionally, authentication cookies are set before the role check, meaning the auth cookies for non-patient users (including administrators) are also set in the HTTP response headers, even though a 403 response is returned.
How severe is CVE-2026-2991?
CVE-2026-2991 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-2991 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-2991?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-2991 have an EU (EUVD) identifier?
Yes. CVE-2026-2991 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-12838.
When was CVE-2026-2991 published?
CVE-2026-2991 was published on 2026-03-18 and last updated on 2026-06-17.

References

Other CWE-287 (Improper Authentication) vulnerabilities

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