CVE-2026-82843
WP OAuth Server < 6.4.0 - Subscriber+ Cross-User Account Takeover via OIDC ID Token Substitution
- Critical 9.0
- A public exploit reference is 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.
Key facts
- Published
- 23 Sep 2026
- Last changed
- 23 Sep 2026
- Assigned by
- WPScan
- EPSS
- 0.188% likely to be exploited in the next 30 days, higher than 8.515% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: none; Automatable: no; Technical impact: total
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 9.0CVSS 3.1, Criticalfrom CISA (ADP container)
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
No explicit remediation statement is available on this page yet. Consult the original record and vendor references before choosing a fix.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Unknown | WP OAuth Server ( Login with WordPress ) |
|
Timeline
- 23 Sep 2026 Published