CVE-2026-12256 WordPress Fusion Builder plugin <= 3.15.3 - PHP Object Injection vulnerability
An attacker can exploit PHP object injection in the Fusion Builder plugin to potentially execute arbitrary code on the WordPress site.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-12256?
CVE-2026-12256 is a high-severity unsafe deserialization vulnerability in ThemeFusion Fusion Builder, published on 16 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Deserialization of Untrusted Data vulnerability in ThemeFusion Fusion Builder fusion-builder allows Object Injection.This issue affects Fusion Builder: from n/a through 3.15.3.
Weakness: CWE-502
Which versions are affected by CVE-2026-12256?
How do I fix CVE-2026-12256?
No fix has been published for CVE-2026-12256 yet. Limit exposure of the affected software until one is available.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-12256 being exploited?
There is no known exploitation of CVE-2026-12256 in the wild and no public exploit code.
Sources
Also known as GHSA-5fx4-xh92-6xqm.