CVE-2026-77194
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk35th percentile - higher than 35% of all known CVEs
Summary
The Simple Membership plugin for WordPress is vulnerable to Authentication Bypass leading to Administrator Account Takeover in versions up to, and including, 4.8.0. This is due to improper identity verification during the public registration flow in WordPress Multisite environments, where the plugin binds new Simple Membership records to existing global WordPress users based solely on matching username and email, without requiring password verification or ownership proof, and fails to properly detect Administrator roles on child sites. This makes it possible for unauthenticated attackers to take over Administrator accounts on child sites in a Multisite network by registering a Simple Membership account with a victim's credentials on a site where public registration is enabled, then updating the victim's global WordPress password through the profile edit functionality. The vulnerability was partially patched in version 4.8.1.
Risk Assessment
Administrator account takeover can lead to full site compromise, including data theft, content modification, and further attacks on users.
Recommendation
Update the Simple Membership plugin to version 4.8.1 or later, and if possible, disable public registration in Multisite environments or enforce additional identity verification.
Other vulnerabilities in Simple Membership
See all- CVE-2026-74000Medium
Broken Access Control vulnerability in Simple Membership plugin up to version 4.8.2, allowing Contributor accounts to access admin functions. This enables privilege escalation.
- CVE-2026-15930Critical
The Simple Membership WordPress plugin before version 4.7.8 does not verify whether user creation failed during registration before using the returned value as a user ID to update an account. This allows unauthenticated attackers to overwrite the primary administrator's account data (including the email address) and take over that account through the password reset flow.
- CVE-2026-88764Medium
The Simple Membership WordPress plugin before 4.7.8 does not validate that the membership level supplied in a PayPal payment notification matches the level configured for the paid payment button. This allows members to pay for a lower-priced membership while being granted a higher, more privileged membership level.
- CVE-2026-14936Medium
The Simple Membership WordPress plugin before 4.7.7 does not verify that a PayPal payment notification was sent to the site's own configured merchant account before activating a membership. This allows unauthenticated users to activate or extend a membership using a payment made to an arbitrary PayPal account they control.
- CVE-2026-66712High
Unauthenticated Broken Access Control in Simple Membership <= 4.7.8 versions.
- CVE-2026-15931Medium
The Simple Membership WordPress plugin before version 4.7.8 does not sanitize a subscriber name value received from an unauthenticated payment approval request, nor escape it when displaying it in the administration dashboard. This allows unauthenticated attackers to store arbitrary JavaScript that executes in an administrator's session.
- CVE-2026-11855High
The Simple Membership WordPress plugin before version 4.7.5 does not verify the authenticity of Stripe webhook requests when no signing secret is configured, nor escapes a value taken from them before outputting it in an administrator notice, allowing unauthenticated attackers to inject arbitrary web scripts that execute in the context of a logged-in administrator.
- CVE-2026-42663Medium
There is an unauthenticated Cross Site Scripting (XSS) vulnerability in Simple Membership versions <= 4.7.2. An attacker can exploit this flaw to inject malicious scripts.
- CVE-2026-34886High
Simple Membership versions up to 4.7.1 have a vulnerability in access control that allows unauthorized access.
Original NVD description (English source)
The Simple Membership plugin for WordPress is vulnerable to Authentication Bypass leading to Administrator Account Takeover in versions up to, and including, 4.8.0. This is due to improper identity verification during the public registration flow in WordPress Multisite environments, where the plugin binds new Simple Membership records to existing global WordPress users based solely on matching username and email, without requiring password verification or ownership proof, and fails to properly detect Administrator roles on child sites. This makes it possible for unauthenticated attackers to take over Administrator accounts on child sites in a Multisite network by registering a Simple Membership account with a victim's credentials on a site where public registration is enabled, then updating the victim's global WordPress password through the profile edit functionality. The vulnerability was partially patched in version 4.8.1.