WordPressプラグイン「DearFlip – PDF Flipbook, 3D Flipbook, PDF embed, PDF viewer」にクロスサイトスクリプティング（XSS）の脆弱性（CVE-2026-8623）
概要
WordPressプラグイン「DearFlip – PDF Flipbook, 3D Flipbook, PDF embed, PDF viewer」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 2.4.30 以前に影響があります。
修正版 2.4.37 への更新が推奨されます。
脆弱性の基本情報
| 脆弱性ID |
CVE-2026-8623 WF-27e2848d-6271-4bb9-92e2-0f8c8860745d |
|---|---|
| 脆弱性の種類 | クロスサイトスクリプティング（XSS） |
| 危険度 | 中 |
| CVSSスコア |
6.4（CVSS v3.1） CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
| 公開日 | 2026年9月4日 |
| 更新日 | 2026年9月5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「DearFlip – PDF Flipbook, 3D Flipbook, PDF embed, PDF viewer」 |
2.4.30 以前 | 2.4.37 | Wordfence Intelligence |
推奨対応
- WordPressプラグイン「DearFlip – PDF Flipbook, 3D Flipbook, PDF embed, PDF viewer」を修正版 2.4.37 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
Dear Flipbook <= 2.4.30 - Authenticated (Contributor+) Stored Cross-Site Scripting via '.dvcss' Element Class Attribute
The Dear Flipbook – PDF Flipbook, 3D Flipbook, PDF embed, PDF viewer plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'post_content (class attribute of .dvcss element)' parameter in all versions up to, and including, 2.4.30 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The payload is embedded as a Base64-encoded JSON object in a CSS class name on a Custom HTML block; the frontend parseCSSElements() function decodes it client-side with atob() and JSON.parse() and renders the logo property as raw HTML, meaning no server-side or client-side sanitization intercepts the malicious script before DOM insertion.
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