AI enriched 7 days ago (2026-04-09 07:21 UTC)

Technical Summary

The OAuth Single Sign On – SSO (OAuth Client) plugin for WordPress is vulnerable to Improper Verification of Cryptographic Signature in versions up to, and including, 6.26.12. This is due to the plugin performing unsafe JWT token processing without verification or validation in the `get_resource_owner_from_id_token` function. This makes it possible for unauthenticated attackers to bypass authentication and gain access to any existing user account - including administrators in certain configurations - or to create arbitrary subscriber-level accounts.

Potential Impact

Severity is CRITICAL (CVSS 9.8). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.

Exploitability Assessment

Exploitability is assessed as Very High based on remote code execution potential, low-bar exploit prerequisites.

Primary risk drivers: remote code execution potential, low-bar exploit prerequisites

Mitigation Recommendations

Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.

Detection & Monitoring

Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.

Business Impact Lens

Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.