# Paytium: Mollie payment forms & donations <= 5.0.5 - Unauthenticated PHP Object Injection via Payment Form Field Values

- **ID:** WPSEC-2026-1473
- **Plugin:** Paytium: Mollie payment forms & donations (`paytium`), https://wordpress.org/plugins/paytium/
- **Affected versions:** all versions before 5.0.6
- **Fixed in:** 5.0.6 (Update to 5.0.6 or later.)
- **Severity:** High 8.1 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)
- **Weakness:** CWE-502
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-10-22)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/paytium
- **Fix released:** 2026-10-21
- **Published:** 2026-10-22
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1473/

## Description

The Paytium: Mollie payment forms & donations plugin for WordPress is vulnerable to PHP Object Injection via the pt_form_field payment form parameters (checkbox fields and the pt-uploaded-files key) in all versions up to, and including, 5.0.5, due to deserialization of untrusted input with maybe_unserialize() without restricting allowed classes. This makes it possible for unauthenticated attackers to inject a PHP object. No known POP chain is present in the plugin itself. If a POP chain is present through another plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code.

## References

- https://wpsec.com/vuln/WPSEC-2026-1473/
- https://plugins.svn.wordpress.org/paytium/tags/5.0.6/
- https://wordpress.org/plugins/paytium/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1473/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.