CVE-2026-8623Medium· 6.4▾ Sunlit

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…

▾ Sunlit zone — Low / medium · no exploitation signal

Depth score35/ 100 · Low

impact 35.2 · likelihood 0 · exploitation 0

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Proof of concept

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Published

Sep 5, 2026

Updated

Sep 8, 2026

CVSS

6.4

Vendor

—

Product

—

CWE

CWE-79

Depth score

35 · Low

EPSS

0.21% · p12

Platforms

—

Source

NVD

Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

EPSS history

Exploit-prediction probability, daily snapshots since Sep 6.

0.2% → 0.2%

Timeline

Disclosure to exploitation, from the record and what we observed since indexing it.

3 events · 3 days

Sep 5, 2026Published
Disclosed via NVD
Sep 6, 2026EPSS first tracked
0.2%
Sep 8, 2026Record revised
Last analysed / modified upstream

CWE-79 #nvd

Full technical detail▾

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.

References

Related vulnerabilities

Connected by shared product, vendor, weakness, or advisory.

#nvd

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