---
id: CVE-2026-12256
title: >-
  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.
summary: >-
  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.
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-502
vendor: ThemeFusion
product: fusion-builder
affected:
  - fusion-builder <= 3.15.3
published: '2026-06-17'
updated: '2026-10-01'
sourceUpdated: '2026-10-01T17:17:19.583'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-12256'
references:
  - url: >-
      https://patchstack.com/database/wordpress/plugin/fusion-builder/vulnerability/wordpress-avada-theme-3-15-3-php-object-injection-vulnerability?_s_id=cve
    label: audit@patchstack.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-06-17T10:29:03.591684Z'
epss: 0.00468
epssPercentile: 0.38237
ingestedAt: '2026-10-01T18:55:42.320Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.