CVE-2026-8623

MediumCVSS 6.4

Published: 05/09/2026(UTC)Updated: 08/09/2026(UTC)Translated: 05/09/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.21%

11th percentile - higher than 11% of all known CVEs

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 including 2.4.30 due to insufficient input sanitization and output escaping. This allows authenticated attackers with contributor-level access and above to inject arbitrary web scripts that execute when 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.

Risk Assessment

The risk includes user session hijacking, data theft, and malware distribution within the context of a trusted WordPress site.

Recommendation

Update the plugin to the latest patched version. Also restrict user privileges and follow secure coding practices.

Other vulnerabilities in Dear Flipbook

CVE-2026-8625Medium
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 (Custom HTML block inner HTML)' parameter in all versions up to and including 2.4.30 due to insufficient input sanitization and output escaping. This allows authenticated attackers with contributor-level access and above to inject arbitrary web scripts that execute when a user accesses an injected page. A Contributor-level attacker can insert a crafted .df-element div with data-df-lightbox='thumb' via a Custom HTML block, whose inner HTML is passed as the title argument to parseThumbs() at render time, enabling both innerHTML injection into a span element and attribute breakout via an onerror handler on a constructed img element.

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS