MetaSlider Vulnerability: Object Injection via Deserialization of Untrusted Data

The National Vulnerability Database has issued an advisory for CVE-2026-39467, a critical deserialization of untrusted data vulnerability affecting MetaSlider Responsive Slider versions up to 3.106.0. This flaw, rated with a CVSS score of 7.2 (HIGH), enables object injection, which can lead to severe consequences for affected WordPress sites.

This vulnerability allows authenticated attackers with high privileges (PR:H) to execute arbitrary code or manipulate application logic by injecting malicious objects. The attacker’s calculus here is straightforward: gain a foothold through a compromised admin account or a weak plugin, then escalate privileges or achieve remote code execution (RCE) via this deserialization flaw. The impact is significant, with high confidentiality, integrity, and availability impacts (C:H/I:H/A:H).

Defenders must prioritize patching. If you’re running MetaSlider Responsive Slider, you need to update immediately. Beyond patching, this highlights a broader architectural weakness: insecure deserialization is a gift that keeps on giving for attackers. CISOs should be scrutinizing their application portfolios for similar deserialization patterns, particularly in WordPress environments, and ensuring robust input validation and secure coding practices are enforced.