XSS in Firelightwp Firelight Lightbox

CVE-2026-6454

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (28.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-6454: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-6454?
CVE-2026-6454 is a medium-severity vulnerability in Firelightwp Firelight Lightbox, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-07-24.
How severe is CVE-2026-6454?
Medium severity. CVSS v3 base score is 6.4 out of 10.