Landing Page Builder <= 1.5.3.6 - Cross-Site Request Forgery to ulpb_admin_data AJAX Action
The Landing Page Builder – Coming Soon page, Maintenance Mode, Lead Page, WordPress Landing Pages plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 1.5.3.6. This is due to missing or incorrect nonce validation on the ulpb_admin_ajax function. This makes it possible for unauthenticated attackers to create, update, retitle, or change the post status, slug, and type of arbitrary posts and write ULPB_DATA post meta via a forged request granted they can trick a site administrator into performing an action such as clicking on a link. This attack requires the victim to hold an editor-level or administrator session, as the wp_ajax_ulpb_admin_data action enforces a capability check that the forged request must satisfy by inheriting the logged-in user's session cookies.
Quick answer
Landing Page Builder – Coming Soon page, Maintenance Mode, Lead Page, WordPress Landing Pages 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
- *-1.5.3.6
Fixed versions
- 1.5.3.7
How to fix it
Landing Page Builder – Coming Soon page, Maintenance Mode, Lead Page, WordPress Landing Pages is affected by this security issue. The safest fix is to update to the fixed version, then test the site or service again to make sure the risky path is closed.
- Find every place where Landing Page Builder – Coming Soon page, Maintenance Mode, Lead Page, WordPress Landing Pages is installed or used.
- Update to 1.5.3.7 or a later vendor-supported version.
- Back up the site or service before changing production systems.
- Apply the update in staging first if possible, then deploy it to production.
- If you cannot update right away, restrict access to the affected feature and monitor logs closely.
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Verify the fix
- Confirm the installed version or configuration is no longer in the affected range.
- Retest the affected page, API, plugin, workflow, or network path.
- Check logs after the change for blocked attempts, crashes, or errors.
- Run a fresh Fixnx scan and save the report.
Related categories
Trusted references
FAQ
What is affected by CVE-2026-12409?
Landing Page Builder – Coming Soon page, Maintenance Mode, Lead Page, WordPress Landing Pages versions listed as affected should be reviewed: *-1.5.3.6.
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.
How are Fixnx security risk categories chosen?
Fixnx keeps one canonical risk page and assigns only broad, relevant categories such as ecosystem, technology area, or vulnerability class.