Arbitrary file upload in Linknacional Pix For Woocommerce

CVE-2026-3891

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.

Vulnerability class: Unrestricted File Upload

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.297 (98.1th percentile), scored .

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 98th percentile — 98.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-3891: rose from 0.251 to 0.297.

EPSS over last 30 days · oldest: 0.251 · newest: 0.297 · change: +0.047

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-3891?
CVE-2026-3891 is a critical-severity vulnerability in Linknacional Pix For Woocommerce, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2026-03-13.
How severe is CVE-2026-3891?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2026-3891 known to be exploited?
10 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.