Vulnerability in Wp Express Checkout

CVE-2026-83537

The WP Express Checkout WordPress plugin before 2.5.0 does not verify server-side that a payment was actually completed before marking an order as paid, allowing unauthenticated users to forge a completed order without paying.

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: 0.002 (5.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 5.2% 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-2026-83537: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

  • Wp Express Checkout

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-83537?
CVE-2026-83537 is a medium-severity vulnerability in Wp Express Checkout, classified under Insufficient Verification of Data Authenticity. CVSS score: 5.3/10. Published 2026-09-09.
How severe is CVE-2026-83537?
Medium severity. CVSS v3 base score is 5.3 out of 10.