CVE-2026-82843

WP OAuth Server < 6.4.0 - Subscriber+ Cross-User Account Takeover via OIDC ID Token Substitution

Published Sep 23, 2026 CVSS 3.1 · 9 Critical EPSS < 1% KEV · Not listed
Description
The WP OAuth Server ( Login with WordPress ) WordPress plugin before 6.4.0 does not bind the OpenID Connect identity assertion it issues to the authorization grant being exchanged, returning instead the assertion belonging to whichever user authenticated most recently, which allows users with the Subscriber role and above to obtain a validly signed identity assertion for another user, including an administrator, and authenticate as them at any application that uses the site for single sign-on.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Wordpress-extensions
Wordpress-extensions wp Oauth Server
Vendors & Products Wordpress-extensions
Wordpress-extensions wp Oauth Server
Type Values Removed Values Added
Description The WP OAuth Server ( Login with WordPress ) WordPress plugin before 6.4.0 does not bind the OpenID Connect identity assertion it issues to the authorization grant being exchanged, returning instead the assertion belonging to whichever user authenticated most recently, which allows users with the Subscriber role and above to obtain a validly signed identity assertion for another user, including an administrator, and authenticate as them at any application that uses the site for single sign-on.
Title WP OAuth Server < 6.4.0 - Subscriber+ Cross-User Account Takeover via OIDC ID Token Substitution
Weaknesses CWE-287
References
Metrics cvssV3_1

{'score': 9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
WPScan
Published
Updated
Sep 23, 2026, 10:58 AM
Reserved
Aug 31, 2026, 8:27 AM
Status
Deferred
Published
Sep 23, 2026, 6:17 AM
Modified
Sep 24, 2026, 2:43 PM