WordPressプラグイン「Simple Membership」に不適切な認証の脆弱性（CVE-2026-77194）
概要
WordPressプラグイン「Simple Membership」に不適切な認証の脆弱性が確認されました。
バージョン 4.8.1 以前に影響があります。
修正版 4.8.2 への更新が推奨されます。
脆弱性の基本情報
| 脆弱性ID |
CVE-2026-77194 WF-ccd3eae5-3d30-4d0d-8f95-5f0747e4e944 |
|---|---|
| 脆弱性の種類 | 不適切な認証 |
| 危険度 | 中 |
| CVSSスコア |
5.3（CVSS v3.1） CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
| 公開日 | 2026年8月31日 |
| 更新日 | 2026年9月1日 |
影響を受ける製品
| 製品 | 影響を受けるバージョン | 修正版 | 出典 |
|---|---|---|---|
| WordPressプラグイン「Simple Membership」 |
4.8.1 以前 | 4.8.2 | Wordfence Intelligence |
推奨対応
- WordPressプラグイン「Simple Membership」を修正版 4.8.2 またはそれ以降の公式最新版へ更新してください。
情報元の原文
Wordfence Intelligence
Simple Membership <= 4.8.1 - Unauthenticated Authentication Bypass to Administrator Account Takeover via Multisite Identity Binding
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.
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