WordPressプラグイン「LiteSpeed Cache」にクロスサイトスクリプティング（XSS）の脆弱性（CVE-2026-18978）
概要
WordPressプラグイン「LiteSpeed Cache」にクロスサイトスクリプティング（XSS）の脆弱性が確認されました。
バージョン 7.8.1 以前に影響があります。
修正版 7.9 への更新が推奨されます。
脆弱性の基本情報
| 脆弱性ID |
CVE-2026-18978 WF-0b045f3d-8412-4e35-b369-2b485639274d |
|---|---|
| 脆弱性の種類 | クロスサイトスクリプティング（XSS） |
| 危険度 | 高 |
| CVSSスコア |
7.2（CVSS v3.1） CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
| 公開日 | 2026年8月27日 |
| 更新日 | 2026年8月28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「LiteSpeed Cache」 |
7.8.1 以前 | 7.9 | Wordfence Intelligence |
推奨対応
- WordPressプラグイン「LiteSpeed Cache」を修正版 7.9 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
LiteSpeed Cache <= 7.8.1 - Unauthenticated Stored Cross-Site Scripting via Comment Content
The LiteSpeed Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content in all versions up to, and including, 7.8.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. A comment payload crafted exclusively from decimal numeric character references (e.g. ", <, >) placed inside an allowed element such as <code> bypasses WordPress's wp_kses sanitization, as kses does not treat a data-settings="..." substring within text content as an HTML attribute, allowing the malicious payload to reach the vulnerable function. For this to be exploitable, the site must allow users with previously approved comments to write new comments, and the require_name_email setting must be disabled.
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