WP OAuth Server < 6.4.0 - Subscriber+ Cross-User Account Takeover via OIDC ID Token Substitution
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-287.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Unknown | WP OAuth Server ( Login with WordPress ) | before 6.4.0 | 6.4.0 | Patch available | CNA |
- WP OAuth Server ( Login with WordPress ) VendorUnknown Affected before 6.4.0 Fixed in 6.4.0 Patch available CNA
Remediation
- Fix · CNA WP OAuth Server ( Login with WordPress ) (Unknown) Fixed in 6.4.0
Timeline
- 2026-10-02 Threatist record created from CVE-2026-82843
- 2026-10-03 Alias added: GHSA-rwfr-37x7-2rr8
References
Sources
- CVE-2026-82843 · CVE Program
- CVE-2026-82843 · NVD
- FIRST EPSS
- GHSA-rwfr-37x7-2rr8 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences