WordPressプラグイン「Subscribe to Comments」に不適切な入力確認の脆弱性（CVE-2026-91831）
概要
WordPressプラグイン「Subscribe to Comments」に不適切な入力確認の脆弱性が確認されました。
バージョン 2.3 以上 2.3.2 以下に影響があります。
修正版 2.3.3 への更新が推奨されます。
脆弱性の基本情報
| 脆弱性ID |
CVE-2026-91831 WF-9423e0a7-d5cf-4a67-b792-7685bf731015 |
|---|---|
| 脆弱性の種類 | 不適切な入力確認 |
| 危険度 | 中 |
| CVSSスコア |
4.3（CVSS v3.1） CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N |
| 公開日 | 2026年10月20日 |
| 更新日 | 2026年10月23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「Subscribe to Comments」 |
2.3 以上 2.3.2 以下 | 2.3.3 | Wordfence Intelligence |
推奨対応
- WordPressプラグイン「Subscribe to Comments」を修正版 2.3.3 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
Subscribe to Comments 2.3 - 2.3.2 - Authenticated (Author+) Arbitrary Email Header Injection
The Subscribe to Comments plugin for WordPress is vulnerable to Email Header Injection in versions 2.3 through 2.3.2. This is due to missing newline sanitization on the notification sender-name setting before it is used in e-mail headers, combined with the absence of type-enforcement guards that prevented sanitize_text_field() from running reliably on the name field. This makes it possible for authenticated attackers, with author-level access and above, to inject arbitrary e-mail headers, such as a hidden Bcc field or a spoofed sender address, into notification e-mails sent to subscribers. The attacker must hold at least Author-level access to reach the settings form.
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