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Findings

Vulnerability · CVE-2026-6279

The Avada Builder (fusion-builder) plugin for WordPress is vulnerable to Unauthenticated Remote Code Execution via PHP Function Injection in versions up to and including 3.15.2.

Published May 21, 2026 · corrected/updated Oct 13, 2026 · theme-fusion avada_builder · evidence confidence very high

The Avada Builder (fusion-builder) plugin for WordPress is vulnerable to Unauthenticated Remote Code Execution via PHP Function Injection in versions up to and including 3.15.2. This is due to the case in passing attacker-controlled values from a base64-decoded JSON blob directly to without any allowlist validation. This is exploitable by unauthenticated attackers through the AJAX endpoint, which is registered for non-privileged (unauthenticated) users via . The endpoint is protected only by a nonce ( ), but this nonce is generated for user ID 0 and is deterministically exposed in the JavaScript output of any public-facing page containing a Post Cards ( ) or Table of Contents ( ) element. This makes it possible for unauthenticated attackers to execute arbitrary code on affected sites.

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2026-6279 is a critical public vulnerability record for theme-fusion avada_builder. CISA lists it as known exploited. Published remediation guidance: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether theme-fusion avada_builder is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: theme-fusion avada_builder. Published remediation guidance: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 9.8, EPSS 2.4%. CISA lists it as known exploited. Weakness classes: CWE-74. Sources contributing to this record: cve_org, epss, nvd, vulncheck_kev. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Confirmed in CISA KEV since Oct 13, 2026. Listed in CISA KEV and VulnCheck KEV.

  • Patch and remediation

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Technology hubs

WordPress

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. May 21, 2026 · NIST NVD

    Detected

    The Avada Builder (fusion-builder) plugin for WordPress is vulnerable to Unauthenticated Remote Code Execution via PHP Function Injection in versions up to and including 3.15.2. This is due to the case in passing attacker-controlled values from a base64-decoded JSON blob directly to without any allowlist validation. This is exploitable by unauthenticated attackers through the AJAX endpoint, which

  2. Jul 23, 2026 · NIST NVD

    Updated

    The Avada Builder (fusion-builder) plugin for WordPress is vulnerable to Unauthenticated Remote Code Execution via PHP Function Injection in versions up to and including 3.15.2. This is due to the case in passing attacker-controlled values from a base64-decoded JSON blob directly to without any allowlist validation. This is exploitable by unauthenticated attackers through the AJAX endpoint, which

  3. Oct 13, 2026 · CISA KEV

    Known exploited

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

  4. Oct 13, 2026 · VulnCheck KEV

    Updated

    The Avada Builder (fusion-builder) plugin for WordPress is vulnerable to Unauthenticated Remote Code Execution via PHP Function Injection in versions up to and including 3.15.2. This is due to the case in passing attacker-controlled values from a base64-decoded JSON blob directly to without any allowlist validation. This is exploitable by unauthenticated attackers through the AJAX endpoint, which

Affected

  • vendor theme-fusion avada_builderversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2026-6279

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-6279

    30-day exploitation probability 2.4%

    first.org
  • NIST NVDVulnerability recordCVE-2026-6279

    The Avada Builder (fusion-builder) plugin for WordPress is vulnerable to Unauthenticated Remote Code Execution via PHP Function Injection in versions up to and including 3.15.2. This is due to the case in `Fusion_Builder_Conditional_Render_Helper::get_value(

    nvd.nist.gov
  • VulnCheck KEVConfirmed exploitationCVE-2026-6279

    The Avada Builder (fusion-builder) plugin for WordPress is vulnerable to Unauthenticated Remote Code Execution via PHP Function Injection in versions up to and including 3.15.2. This is due to the case in passing attacker-controlled values from a base64-decoded JSON blob directly

    vulncheck.com

References