CVE-2023-5621: The Thumbnail Slider With Lightbox plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Image Title field in versions up to, and ...

Description

The Thumbnail Slider With Lightbox plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Image Title field in versions up to, and including, 1.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level access, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.

Metrics

CVSS 3.1

4.8/10

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

EPSS Probability

0.40%

31.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
I13websolution	Thumbnail Slider With Lightbox	1.0

References

Timeline

Published: Oct 18, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-5621?

The Thumbnail Slider With Lightbox plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Image Title field in versions up to, and including, 1.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level access, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.

How severe is CVE-2023-5621?

CVE-2023-5621 has a CVSS score of 4.8/10 (MEDIUM severity). The EPSS model estimates a 0.40% probability of exploitation in the next 30 days.

How do I fix CVE-2023-5621?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.