CVE-2023-2733Known exploitationNetwork attack vector

Account takeover via unverified coupon user ID

Published May 25, 2023 · Updated Apr 8, 2026

Authentication bypass in FluxBuilder MStore API 3.9.0 and earlier allows remote attackers to log in as any existing user via a REST request. The coupon redemption handler accepts a supplied user ID without sufficiently verifying that the requester controls that account. No authentication is required; knowledge of an administrator's user ID grants that account's WordPress privileges.

CVSS severity9.8
Critical
EPSS probability1.25%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Authentication bypass in FluxBuilder MStore API 3.9.0 and earlier allows remote attackers to log in as any existing user via a REST request. The coupon redemption handler accepts a supplied user ID without sufficiently verifying that the requester controls that account. No authentication is required; knowledge of an administrator's user ID grants that account's WordPress privileges.

The record

CVE
CVE-2023-2733
Published
May 25, 2023
Updated
Apr 8, 2026
Vendor
FluxBuilder
Product
MStore API
Classifications
CWE-288, T1078
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 25, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=3.9.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FluxBuilder · MStore APIversion=0 <=3.9.0

Published CVSS scores

9.8WordfenceCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-288Authentication Bypass Using an Alternate Path or Channel
T1078Valid Accounts

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo