WordPressプラグイン「Ultimate Multisite – WordPress Multisite SaaS & WaaS Platform」に不適切な認証の脆弱性（CVE-2026-103646）
概要
WordPressプラグイン「Ultimate Multisite – WordPress Multisite SaaS & WaaS Platform」に不適切な認証の脆弱性が確認されました。
バージョン 2.16.0 以前に影響があります。
修正版 2.17.0 への更新が推奨されます。
脆弱性の基本情報
| 脆弱性ID |
CVE-2026-103646 WF-d9bb5fdb-939c-4c94-aa4e-fe56b45add5f |
|---|---|
| 脆弱性の種類 | 不適切な認証 |
| 危険度 | 高 |
| CVSSスコア |
7.3（CVSS v3.1） CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
| 公開日 | 2026年10月6日 |
| 更新日 | 2026年10月13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「Ultimate Multisite – WordPress Multisite SaaS & WaaS Platform」 |
2.16.0 以前 | 2.17.0 | Wordfence Intelligence |
推奨対応
- WordPressプラグイン「Ultimate Multisite – WordPress Multisite SaaS & WaaS Platform」を修正版 2.17.0 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
Ultimate Multisite <= 2.16.0 - Unauthenticated Arbitrary Account Takeover
The Ultimate Multisite plugin for WordPress is vulnerable to Account Takeover in all versions up to, and including, 2.16.0. This is due to missing email normalization before the duplicate-account lookup combined with the absence of a require_new_user guard, allowing a submitted email to be matched to and linked with an existing WordPress user account without authentication. This makes it possible for unauthenticated attackers to log in as any existing WordPress user, including a Network Super Admin, by submitting their known email address through a passwordless checkout form and having the plugin link the unauthenticated checkout session to that existing account. A checkout form must be configured without a password field (auto-generated password mode), and the targeted WordPress account must have no existing customer record in the plugin.
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