CVE-2026-4665

Description

The WP Carousel Free plugin for WordPress is vulnerable to Stored Cross-Site Scripting via crafted fancybox `data-caption` attributes in all versions up to, and including, 2.7.10. This is due to the `fancybox-config.js` script reading the carousel container's `id` attribute directly from the DOM to construct a jQuery selector without sanitization. When a Contributor crafts an HTML block with a malformed carousel container ID (containing characters invalid for jQuery selectors), the custom fancybox configuration throws a JavaScript error and fails to initialize. This causes the bundled fancybox library (v3.5.7) to fall back to its default caption handling, which renders the `data-caption` attribute content as raw HTML. Since WordPress allows `data-*` attributes through `wp_kses_post()`, 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 clicks an image in the crafted carousel lightbox.

CVSS v3.1 Score

6.4

MEDIUM

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

EPSS — Exploit Prediction

0.0003

Probability of exploitation

0.10%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Other References

https://plugins.trac.wordpress.org/browser/wp-carousel-free/tags/2.7.10/public/js/fancybox-config.js#L3 https://plugins.trac.wordpress.org/browser/wp-carousel-free/trunk/public/js/fancybox-config.js#L3 https://plugins.trac.wordpress.org/changeset/3506878/wp-carousel-free/trunk/public/js/fancybox.js https://www.wordfence.com/threat-intel/vulnerabilities/id/e75815a3-2414-47f3-b0c4-e5d3e2cb369d?source=cve

Frequently Asked Questions

What is CVE-2026-4665? +

The WP Carousel Free plugin for WordPress is vulnerable to Stored Cross-Site Scripting via crafted fancybox `data-caption` attributes in all versions up to, and including, 2.7.10. This is due to the `fancybox-config.js` script reading the carousel container's `id` attribute directly from the DOM to construct a jQuery selector without sanitization. When a Contributor crafts an HTML block with a malformed carousel container ID (containing characters invalid for jQuery selectors), the custom fancybox configuration throws a JavaScript error and fails to initialize. This causes the bundled fancybox library (v3.5.7) to fall back to its default caption handling, which renders the `data-caption` attribute content as raw HTML. Since WordPress allows `data-*` attributes through `wp_kses_post()`, 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 clicks an image in the crafted carousel lightbox. It has a CVSS v3.1 base score of 6.4 (MEDIUM).

How severe is CVE-2026-4665? +

CVE-2026-4665 has a CVSS v3.1 score of 6.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0003, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-4665? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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