WordPress security changelog
MEDIUM CVE-2026-6454 Deferred

Firelight PDF links allow contributor stored DOM XSS

A contributor can store a PDF link whose entity-encoded quotes break out when Firelight Lightbox's FancyBox V2 beforeLoad callback concatenates this.href into object/embed HTML. The resulting event-handler markup executes when a visitor clicks the link. The CNA lists releases through 2.3.20 as affected, although the currently served official 2.3.20 package already uses safe jQuery element construction while 2.3.18 is demonstrably vulnerable.

CVE / CNA score 6.4 CVSS 3.1 · security@wordfence.com
NVD score Pending NVD has not published its own CVSS assessment.
Component
Firelight Lightbox
Plugin slug
easy-fancybox
Affected
<= 2.3.20
Safe version
2.3.21
Published
Jul 24, 2026
Weakness
CWE-79 — Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

This CVE was published Jul 24, 2026 and is one of 3 known issues for this plugin.

What to do

Update, patch or deactivate.

Use Firelight Lightbox 2.3.21 or later while the CNA version discrepancy remains unresolved. A small application backport can replace HTML-string concatenation with jQuery element creation and .attr() assignment for the object data and embed src values. Review contributor-authored PDF links for encoded quotes or event-handler markup.

A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Source record

Technical description

The Firelight Lightbox plugin for WordPress is vulnerable to Stored DOM Cross-Site Scripting in versions up to and including 2.3.20. This is due to insufficient sanitization of the href attribute value within the FancyBox V2 PDF beforeLoad JavaScript callback generated in inc/fancybox-2.php, where this.href is string-concatenated directly into an HTML string without escaping, allowing a stored href containing entity-encoded double-quotes to break out of the data attribute and inject arbitrary event handlers into the DOM. This makes it possible for authenticated attackers with contributor-level access and above to inject arbitrary web scripts into pages that execute whenever a user clicks the malicious PDF link.

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

References

Primary and upstream sources