{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-5524: Divi Form Builder <= 5.1.8 - Unauthenticated Arbitrary File Upload Leading to Remote Code Execution via 'acceptFileTypes' Parameter","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-5524","status":"final","version":"1","initial_release_date":"2026-07-02T12:34:40.602Z","current_release_date":"2026-07-02T15:00:12.782Z","revision_history":[{"date":"2026-07-02T12:34:40.602Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"The Divi Form Builder plugin for WordPress is vulnerable to Arbitrary File Upload leading to Remote Code Execution in all versions up to and including 5.1.8. This is due to insufficient file extension validation in the do_image_upload() function where user-supplied input from the acceptFileTypes POST parameter is directly interpolated into a regular expression used to validate uploaded files. Attackers can specify PHP-executable extensions such as .phtml, .phar, .php5, or .php7 to bypass the plugin's .htaccess protection which only blocks .php files specifically. Additionally, on Nginx-based servers, the .htaccess protection is completely ineffective as Nginx does not process .htaccess files. This makes it possible for unauthenticated attackers (who can obtain a nonce from any public page containing a form) to upload executable PHP files to the publicly accessible /wp-content/uploads/de_fb_uploads/ directory and achieve Remote Code Execution by accessing the uploaded file via HTTP. The vulnerability was partially patched in version 5.1.3.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-5524 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-5524"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-5524"},{"category":"external","summary":"wordfence.com","url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/9692deb2-2526-4983-8a13-93a382e230c8?source=cve"},{"category":"external","summary":"diviengine.com","url":"https://diviengine.com/divi-form-builder-changelog/"}]},"product_tree":{"branches":[{"category":"vendor","name":"Divi Engine","branches":[{"category":"product_name","name":"Divi Form Builder","branches":[{"category":"product_version_range","name":"<=5.1.8","product":{"name":"Divi Engine Divi Form Builder <=5.1.8","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:divi_engine:divi_form_builder:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-5524","title":"Divi Form Builder <= 5.1.8 - Unauthenticated Arbitrary File Upload Leading to Remote Code Execution via 'acceptFileTypes' Parameter","notes":[{"category":"description","text":"The Divi Form Builder plugin for WordPress is vulnerable to Arbitrary File Upload leading to Remote Code Execution in all versions up to and including 5.1.8. This is due to insufficient file extension validation in the do_image_upload() function where user-supplied input from the acceptFileTypes POST parameter is directly interpolated into a regular expression used to validate uploaded files. Attackers can specify PHP-executable extensions such as .phtml, .phar, .php5, or .php7 to bypass the plugin's .htaccess protection which only blocks .php files specifically. Additionally, on Nginx-based servers, the .htaccess protection is completely ineffective as Nginx does not process .htaccess files. This makes it possible for unauthenticated attackers (who can obtain a nonce from any public page containing a form) to upload executable PHP files to the publicly accessible /wp-content/uploads/de_fb_uploads/ directory and achieve Remote Code Execution by accessing the uploaded file via HTTP. The vulnerability was partially patched in version 5.1.3.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1"]},"scores":[{"cvss_v3":{"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"},"products":["CSAFPID-1"]}],"remediations":[{"category":"none_available","details":"No fixed version is published yet. Monitor the upstream advisory.","product_ids":["CSAFPID-1"]}]}]}