Auth bypass in Wp Oauth Server ( Login With WordPress )

CVE-2026-82843

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.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (7.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 8th percentile — 7.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

  • Wp Oauth Server ( Login With WordPress )

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-82843?
CVE-2026-82843 is a critical-severity vulnerability in Wp Oauth Server ( Login With WordPress ), classified under Improper Authentication. CVSS score: 9.0/10. Published 2026-09-23.
How severe is CVE-2026-82843?
Critical severity. CVSS v3 base score is 9.0 out of 10.