Vulnerability Description
The Flow Payment plugin for WordPress (flow.cl) version 3.0.8 is vulnerable to reflected cross-site scripting on the WooCommerce checkout page. When the plugin handles an order cancellation, the error_message GET parameter is passed directly to wc_add_notice() in flowpayment-fl.php (lines 57-58) without input sanitization (for example sanitize_text_field()) or output escaping (for example esc_html()) before being rendered in the checkout notice HTML. An unauthenticated attacker can craft a URL containing a JavaScript payload in the error_message parameter (for example /checkout/?add-to-cart={product-id}&cancel_order=true&error_message={payload}); when a victim with an active WooCommerce checkout session follows the link, the payload executes in the victim's browser in the origin of the WordPress site.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://www.flow.cl/
- https://www.vulncheck.com/advisories/flow-payment-plugin-for-wordpress-reflected
FAQ
What is CVE-2026-57857?
CVE-2026-57857 is a vulnerability with a CVSS score of 4.3 (MEDIUM). The Flow Payment plugin for WordPress (flow.cl) version 3.0.8 is vulnerable to reflected cross-site scripting on the WooCommerce checkout page. When the plugin handles an order cancellation, the error...
How severe is CVE-2026-57857?
CVE-2026-57857 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-57857?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.