CVE-2026-18467: Paytium: Mollie payment forms & donations <= 5.0.3 - Unauthenticated Privilege Escalation via 'pt_form_field[pt-user-role]' Parameter

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-24 · updated 2026-09-24
Weakness: CWE-269

Description

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.

Affected products

paytiumsupport Paytium: Mollie payment forms & donations: through 5.0.3

References

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