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Paytium - Security Vulnerability (CVE-2026-18467)

CVE-2026-18467

The Paytium: Mollie payment forms & donations plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 5.0.3. The 5.0.3 patch introduced a wp_hash()/hash_equals() signature gate on the pt-paytium-user-data field, but left a second filter — pt_cf_checkout_meta(), registered on the pt_meta_values hook after the signed builder — that copies every $_POST['pt_form_field'][*] key verbatim into the payment meta array without any signature verification; this allows the pt-user-role value it copies to overwrite the signed path's output, after which paytium_user_data_processing() reads the persisted _pt-user-role post meta and passes it directly as the role argument to wp_insert_user(). This makes it possible for unauthenticated attackers to register a new WordPress account with the administrator role and fully take over the site. Exploitation requires submitting a payment through a publicly-exposed [paytium] shortcode form and completing the resulting payment flow, after which the attacker can seize the new administrator account via the standard lost-password flow on their supplied email address.

CVE-2026-18467

CRITICAL CVSS 9.8 Published 2026-09-24 Updated 2026-09-24
AI Risk Critical (100/100) Active Exploit: No strong signal Published Exploit: No public exploit references Priority: P1 Immediate
Severity Band CRITICAL
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Components 2
Reference Links 7
AI Risk Engine Critical (100/100)
Exploitability Very High
Active Exploitation No strong signal
Published Exploit Status No public exploit references

Threat Timeline

  1. 2026-09-24 CVE published and first recorded in the threat feed.
  2. 2026-09-24 Record updated with latest vulnerability metadata.
  3. 2026-10-01 AI technical context refreshed for mitigation and impact guidance.
  4. Now Monitoring for follow-up changes, linked references, and new related CVEs.

AI Context

Machine-generated threat intelligence

AI Updated just now

AI enriched just now (2026-10-01 13:53 UTC)

Technical Summary

The Paytium: Mollie payment forms & donations plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 5.0.3. The 5.0.3 patch introduced a wp_hash()/hash_equals() signature gate on the pt-paytium-user-data field, but left a second filter — pt_cf_checkout_meta(), registered on the pt_meta_values hook after the signed builder — that copies every $_POST['pt_form_field'][*] key verbatim into the payment meta array without any signature verification; this allows the pt-user-role value it copies to overwrite the signed path's output,…

Potential Impact

Severity is CRITICAL (CVSS 9.8). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.

Exploitability Assessment

Exploitability is assessed as Very High based on remote code execution potential, low-bar exploit prerequisites.

Primary risk drivers: remote code execution potential, low-bar exploit prerequisites

Mitigation Recommendations

Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.

Detection & Monitoring

Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.

Business Impact Lens

AI risk score 100/100 (Critical, Very High) with priority P1 Immediate. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.

Affected Products

Paytium PLUGIN · paytium Affected: >= 0, <= 5.0.3 Fixed version not specified
Paytium: Mollie payment forms & donations PLUGIN · paytium-mollie-payment-forms-donations Affected: >= 0, <= 5.0.3 Fixed version not specified

References

What to do about this

Patch immediately Serious, and reachable without meaningful privilege.

Fix it

Update Paytium to the latest available version.

Where the vendor has not published a fix yet, disable the plugin until they do.

Cannot update today? Unauthorised administrator detection in Hack Halt ProSecure blocks this class of attack before WordPress processes the request.

Alert when a new administrator appears or a role is escalated. Creating a hidden admin is the most common persistence step after a WordPress compromise.

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Not sure if you are affected?

Scan your site to see whether it runs Paytium, and at which version.

Free, no installation, no account. It reads what your site already publishes, then tells you which plugins carry known vulnerabilities and what to do about each one.

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Am I affected by this vulnerability?

You are affected if your site runs Paytium. No account is needed to exploit this, so a public site is reachable by anyone.

How do I fix it?

Update Paytium to the latest available version. Where the vendor has not yet published a fix, remove or disable the plugin until they do. Until you can update, Unauthorised administrator detection in Hack Halt ProSecure contains this class of attack at the request layer.

What can an attacker actually do?

This is a Privilege Escalation flaw. An attacker who exploits it can raise a low-privilege account, or none at all, to administrator.