CVE-2026-3347
CWE-79Published: March 21, 2026· Updated: Mar 23, 2026
Official Description
The Multi Functional Flexi Lightbox plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `arv_lb[message]` parameter in all versions up to, and including, 1.2 due to insufficient input sanitization and output escaping. This is due to the `arv_lb_options_val()` sanitize callback returning user input without any sanitization, and the stored `message` value being output in the `genLB()` function without 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 a page or post with the lightbox enabled.
Technical Analysis
CVE-2026-3347 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
All References (5)
Quick Facts
Related CVEs (CWE-79)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-3347 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts