CVE-2026-3651: The Build App Online plugin for WordPress is vulnerable to unauthorized access in all versions up to, and including, 1.0.23. This is due to the plugin...

Description

The Build App Online plugin for WordPress is vulnerable to unauthorized access in all versions up to, and including, 1.0.23. This is due to the plugin registering the 'build-app-online-update-vendor-product' AJAX action via wp_ajax_nopriv_ without proper authentication checks, capability verification, or nonce validation in the update_vendor_product() function. The function accepts a user-supplied post ID from the request and calls wp_update_post() to modify the post_author field without validating whether the user has permission to modify the specified post. This makes it possible for unauthenticated attackers to modify the post_author of arbitrary posts to 0 (orphaning posts from their legitimate authors), or for authenticated attackers to claim ownership of any post by setting themselves as the author.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS Probability

0.30%

22.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-862

References

Timeline

Published: Mar 21, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-3651?

The Build App Online plugin for WordPress is vulnerable to unauthorized access in all versions up to, and including, 1.0.23. This is due to the plugin registering the 'build-app-online-update-vendor-product' AJAX action via wp_ajax_nopriv_ without proper authentication checks, capability verification, or nonce validation in the update_vendor_product() function. The function accepts a user-supplied post ID from the request and calls wp_update_post() to modify the post_author field without validating whether the user has permission to modify the specified post. This makes it possible for unauthenticated attackers to modify the post_author of arbitrary posts to 0 (orphaning posts from their legitimate authors), or for authenticated attackers to claim ownership of any post by setting themselves as the author.

How severe is CVE-2026-3651?

CVE-2026-3651 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.30% probability of exploitation in the next 30 days.

How do I fix CVE-2026-3651?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.