Avada (Fusion) Builder <= 3.15.2 - Unauthenticated Remote Code Execution via PHP Function Injection via 'render_logics' Shortcode Attribute via Widget AJAX Handler_CVE-2026-6279

{
    "lastseen": "",
    "description": "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 `wp_conditional_tags` case in `Fusion_Builder_Conditional_Render_Helper::get_value()` passing attacker-controlled values from a base64-decoded JSON blob directly to `call_user_func()` without any allowlist validation. This is exploitable by unauthenticated attackers through the `fusion_get_widget_markup` AJAX endpoint, which is registered for non-privileged (unauthenticated) users via `wp_ajax_nopriv_fusion_get_widget_markup`. The endpoint is protected only by a nonce (`fusion_load_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 (`[fusion_post_cards]`) or Table of Contents (`[fusion_table_of_contents]`) element. This makes it possible for unauthenticated attackers to execute arbitrary code on affected sites.",
    "published": "2026-05-21T04:27:57.613Z",
    "modified": "2026-05-21T04:27:57.613Z",
    "type": "cve",
    "title": "Avada (Fusion) Builder <= 3.15.2 - Unauthenticated Remote Code Execution via PHP Function Injection via 'render_logics' Shortcode Attribute via Widget AJAX Handler",
    "source": "Wordfence",
    "references": "https://www.wordfence.com/threat-intel/vulnerabilities/id/5dc72d78-d47c-4b36-8d69-8672e15ddf8c?source=cve\nhttps://plugins.trac.wordpress.org/browser/fusion-builder/trunk/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1531\nhttps://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1531\nhttps://plugins.trac.wordpress.org/browser/fusion-builder/trunk/shortcodes/fusion-widget.php#L44\nhttps://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/shortcodes/fusion-widget.php#L44\nhttps://plugins.trac.wordpress.org/browser/fusion-builder/trunk/shortcodes/fusion-widget.php#L389\nhttps://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/shortcodes/fusion-widget.php#L389\nhttps://plugins.trac.wordpress.org/browser/fusion-builder/trunk/inc/class-fusion-builder.php#L7551\nhttps://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/inc/class-fusion-builder.php#L7551\nhttps://plugins.trac.wordpress.org/browser/fusion-builder/trunk/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1083\nhttps://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1083\nhttps://avada.com/documentation/avada-changelog/",
    "id": "CVE-2026-6279",
    "bulletinFamily": "",
    "cwe": [
        "CWE-74"
    ],
    "cvelist": null,
    "sourceData": "themefusion Avada (Fusion) Builder 0",
    "sourceHref": "",
    "cvss": {
        "score": 9.8,
        "severity": "CRITICAL",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Avada (Fusion) Builder",
    "version": "3.15.2",
    "vendor": "themefusion",
    "ai_description": "Unauthenticated Remote Code Execution via PHP Function Injection in Avada Builder plugin",
    "ai_severity": "Critical",
    "ai_vendor": "ThemeFusion",
    "ai_product": "Avada Builder",
    "ai_version": "3.15.2",
    "ai_score": 9.8
}