CVE-2026-82843criticalCWE-287

CVE-2026-82843: critical vulnerability in WP OAuth Server ( Login with WordPress )

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

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48Vexday Risk Score

No sign of exploitation. It has a public proof of concept.

ssvc Attendcvss 9epss 0.2%
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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
Affected products
Unknown · WP OAuth Server ( Login with WordPress )
⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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