OAuth Single Sign On permits arbitrary non-administrator login through Steam SSO
OAuth Single Sign On 6.25.0 through 7.0.0 does not verify the identity assertion returned by its Steam single-sign-on flow. An unauthenticated attacker can log in as an arbitrary non-administrator user or create a new account.
- Component
- OAuth Single Sign On
- Plugin slug
oauth-single-sign-on- Affected
- 6.25.0 to < 7.0.1
- Safe version
7.0.1- Published
- Sep 02, 2026
This CVE was published Sep 02, 2026 and is one of 4 known issues for this plugin.
Update, patch or deactivate.
Update to OAuth Single Sign On 7.0.1 or later, invalidate active sessions, and audit SSO logins and newly created accounts.
A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.
Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.
Technical description
The OAuth Single Sign On WordPress plugin before 7.0.1 does not verify the identity assertion returned by its Steam single sign-on flow, allowing unauthenticated attackers to log in as an arbitrary non-administrator user, and to create new accounts.
CVE / CNA vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H