9.1

CVE-2026-16038: unknown mstore api Missing Authorization

CVSS: 9.1v3.1CriticalDeferred
Published 07-08-2026Last modified 07-08-2026
Open JSON

Vulnerability summary

CVE-2026-16038 is a critical (CVSS 9.1) Missing Authorization vulnerability in unknown mstore api. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 34.6% of scored vulnerabilities. 1 public exploit is recorded. Fixed in 4.21.0.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.1/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.42%
0%100%
Low · +0.18 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference

Timeline

  1. 07-08-2026
    PublishedVulnerability first disclosed.
  2. 07-08-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.42%

Chance of exploitation in the next 30 days

Percentile

35%

Versus all other CVEs

30-day change

+0.18 pp

From 0.24% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.42%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • referenceUnverified

    Exploit Reference (wpscan.com)

    Maturity: unknown

Weaknesses

CWE · root cause

Affected systems

Unknown1 product
Wordpress1 product
  • mstore-api≤ 4.20.0 (fixed in 4.21.0)

2 vendors · 2 products

References

2 links