WP User Frontend Arbitrary Post Overwrite IDOR Vulnerability
The User Frontend: AI Powered Frontend Posting, User Directory, Profile, Membership & User Registration plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 4.3.7 via the 'wpuf_files_data' parameter due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to overwrite the post_title, post_content, and post_excerpt of any arbitrary post on the site, including posts authored by administrators. Exploitation requires access to any WPUF post submission form; this is achievable by users with no WordPress role, as the wpuf_submit_post AJAX action is gated only by a nonce with no capability check for the downstream post-edit operation.
Quick answer
WP User Frontend User Frontend should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.
Who is affected
Affected versions
- User Frontend up to and including 4.3.7
Fixed versions
- Apply the latest vendor-supported patched version.
How to fix it
WP User Frontend is affected by CVE-2026-12418. Versions up to 4.3.7 can allow unauthenticated content tampering because unauthenticated attackers with access to a WPUF form can overwrite arbitrary post title, content, and excerpt values. Patch the plugin and review posts that may have been modified.
- Inventory WordPress sites using WP User Frontend.
- Update WP User Frontend beyond 4.3.7 when a fixed release is available.
- Disable public WPUF submission forms until the site is patched if immediate update is not possible.
- Review recent post title, content, and excerpt changes for unexpected edits.
- Restore tampered posts from revisions or trusted backups.
- Restrict the affected AJAX action and form endpoints with WAF rules during remediation.
- Clear page and CDN caches after restoring content.
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Verify the fix
- Confirm WP User Frontend is no longer version 4.3.7 or older.
- Attempt a safe post ID substitution test in staging and confirm arbitrary posts cannot be overwritten.
- Confirm legitimate front-end submissions still create or edit only permitted posts.
- Review audit logs and post revisions for further tampering after mitigation.
- Run a Fixnx scan and verify public WordPress exposure is rechecked.
Related categories
Trusted references
FAQ
What is affected by CVE-2026-12418?
WP User Frontend User Frontend versions listed as affected should be reviewed: User Frontend up to and including 4.3.7.
What should I fix first?
Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.
How do I confirm the fix worked?
Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.
Why can this risk appear in multiple categories?
A vulnerability can belong to more than one platform or ecosystem. Fixnx keeps one canonical risk page while also listing it in every relevant category.