App Builder <= 5.6.1 — Insecure Direct Object Reference to Authenticated (Subscriber+) Arbitrary User Avatar Modification via 'user_id' Parameter

Am I affected?

• Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under App Builder – Create Native Android & iOS Apps On The Flight.
• No admin access? Run a passive check of your site. It reads public files only.
• No account is needed to exploit this. Treat any exposed site on an affected version as at risk.

What to do

1. Update to version 5.7.0, or a newer patched version
2. Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
3. Watch App Builder – Create Native Android & iOS Apps On The Flight to get an email when the next vulnerability is published.

Advisory

Source description from Wordfence Intelligence, credited to Ren Voza.

The App Builder – Create Native Android & iOS Apps On The Flight plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to and including 5.6.1. This is due to missing authorization validation in the `upload_avatar()` function, which accepts an attacker-controlled `user_id` parameter from the POST request body and uses it to update user meta without verifying that the authenticated requester owns or has permission to modify the target account. This makes it possible for authenticated attackers, with Subscriber-level access and above, to overwrite the profile avatar of any arbitrary user on the site, including administrators, by supplying a target `user_id` in the request body to the `/wp-json/app-builder/v1/upload-avatar` endpoint.

Exploits & references

Proof-of-concept & detection

No public proof-of-concept or detection template is known for this vulnerability.

Advisories & patches

• Advisorywordfence.com

Related CVEs

Timeline

1. May 1, 2026

   CVE published

   Severity medium, CVSS 5.3

2. Nov 13, 2026

   Record last updated