Auth bypass in Mstore API
CVE-2026-16038
The MStore API WordPress plugin before 4.21.0 does not verify the payment with the payment gateway before marking an order as paid on several of its payment-completion endpoints, allowing an unauthenticated attacker to mark an arbitrary order fully paid without paying and obtain goods or services for free.
Vulnerability class: Broken Access Control
EPSS: 0.002 (15.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Unknown Mstore Api — versions 0
Weakness classification (CWE)
References
- contact@wpscan.com (technical-description, exploit, vdb-entry)
Frequently asked questions
- What is CVE-2026-16038?
- CVE-2026-16038 is a critical-severity vulnerability in Mstore API, classified under Missing Authorization. CVSS score: 9.1/10. Published 2026-08-07.
- How severe is CVE-2026-16038?
- Critical severity. CVSS v3 base score is 9.1 out of 10.