---
id: CVE-2026-8623
title: >-
  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 includ…
summary: >-
  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 includ…
severity: medium
cvss: 6.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
published: '2026-09-05'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T13:12:58.310'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-8623'
references:
  - url: >-
      https://plugins.trac.wordpress.org/browser/3d-flipbook-dflip-lite/tags/2.4.27/assets/js/dflip.js#L11255
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/3d-flipbook-dflip-lite/tags/2.4.27/assets/js/dflip.js#L2687
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/changeset/3641463/3d-flipbook-dflip-lite/trunk/assets/js/dflip.js
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/changeset?old_path=%2F3d-flipbook-dflip-lite/tags/2.4.30&new_path=%2F3d-flipbook-dflip-lite/tags/2.4.37
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/changeset?reponame=&new=3641463%403d-flipbook-dflip-lite%2Ftags%2F2.4.37&old=3557511%403d-flipbook-dflip-lite%2Ftags%2F2.4.30
    label: security@wordfence.com
  - url: >-
      https://www.wordfence.com/threat-intel/vulnerabilities/id/27e2848d-6271-4bb9-92e2-0f8c8860745d?source=cve
    label: security@wordfence.com
tags:
  - nvd
epss: 0.00212
epssPercentile: 0.11853
ingestedAt: '2026-09-06T02:48:40.752Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.