Auth bypass in Strablengineering Strabl – A Checkout Solution
CVE-2026-3640
The STRABL – A checkout solution plugin for WordPress is vulnerable to Missing Authentication in all versions up to and including 4.5. The plugin registers a REST API webhook endpoint at /wp-json/strabl/webhook/order with a permission_callback of __return_true, which allows all incoming requests without any authentication or authorization checks. No shared secret, signature validation, HMAC verification, or token-based authentication is implemented. This makes it possible for unauthenticated attackers to create fraudulent WooCommerce orders and mark them as completed by supplying paymentStatus=paid, manipulate existing order statuses by providing an externalOrderId, create new WordPress user accounts with the customer role, issue refunds on existing orders, cancel existing orders, and apply chargeback fees — all without making a legitimate payment or having any valid credentials.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.006 (48.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 48.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Strablengineering Strabl – A Checkout Solution — versions 0
Weakness classification (CWE)
References
- www.wordfence.com/threat-intel/vulnerabilities/id/04eb82e4-1738-44c7-980e-8e33a…
- plugins.trac.wordpress.org/browser/strabl-a-checkout-solution/trunk/src/Orders/…
- plugins.trac.wordpress.org/browser/strabl-a-checkout-solution/tags/4.5/src/Orde…
- plugins.trac.wordpress.org/browser/strabl-a-checkout-solution/trunk/src/Orders/…
- plugins.trac.wordpress.org/browser/strabl-a-checkout-solution/tags/4.5/src/Orde…
- plugins.trac.wordpress.org/browser/strabl-a-checkout-solution/trunk/src/Orders/…
- plugins.trac.wordpress.org/browser/strabl-a-checkout-solution/tags/4.5/src/Orde…
- plugins.trac.wordpress.org/browser/strabl-a-checkout-solution/trunk/src/Orders/…
- plugins.trac.wordpress.org/browser/strabl-a-checkout-solution/tags/4.5/src/Orde…
- plugins.trac.wordpress.org/browser/strabl-a-checkout-solution/trunk/src/Orders/…
Frequently asked questions
- What is CVE-2026-3640?
- CVE-2026-3640 is a medium-severity vulnerability in Strablengineering Strabl – A Checkout Solution, classified under Missing Authorization. CVSS score: 5.3/10. Published 2026-06-19.
- How severe is CVE-2026-3640?
- Medium severity. CVSS v3 base score is 5.3 out of 10.