CVE-2026-3891: Pix for WooCommerce <= 1.5.0 - Unauthenticated Arbitrary File Upload

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 31.8% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-03-13 · updated 2026-06-17
Weakness: CWE-434

Description

The Pix for WooCommerce plugin for WordPress is vulnerable to arbitrary file uploads due to missing capability check and missing file type validation in the 'lkn_pix_for_woocommerce_c6_save_settings' function in all versions up to, and including, 1.5.0. This makes it possible for unauthenticated attackers to upload arbitrary files on the affected site's server which may make remote code execution possible.

Affected products

linknacional Pix for WooCommerce: through 1.5.0

References

https://plugins.trac.wordpress.org/browser/payment-gateway-pix-for-woocommerce/tags/1.4.0/Includes/LknPaymentPixForWoocommercePixC6.php#L694
https://plugins.trac.wordpress.org/changeset/3480639/payment-gateway-pix-for-woocommerce#file56
https://www.wordfence.com/threat-intel/vulnerabilities/id/20188fd3-c330-4c76-912b-72731e14c450?source=cve

Get alerted when CVE-2026-3891 or the next vulnerability affects your stack