CVE-2021-47933Public exploitNetwork attack vector

Unauthenticated code execution via unrestricted config file upload

Published May 10, 2026 · Updated May 10, 2026

Arbitrary file upload in FluxBuilder MStore API 2.0.6 allows remote attackers to execute PHP code through the config_file REST endpoint. The endpoint accepts a multipart file named with a PHP extension and stores it in a web-accessible location without requiring authentication or rejecting the executable suffix. The plugin must be active and the endpoint reachable; successful upload grants server-side code execution in the WordPress host context.

CVSS severity9.3
Critical
EPSS probability0.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Arbitrary file upload in FluxBuilder MStore API 2.0.6 allows remote attackers to execute PHP code through the config_file REST endpoint. The endpoint accepts a multipart file named with a PHP extension and stores it in a web-accessible location without requiring authentication or rejecting the executable suffix. The plugin must be active and the endpoint reachable; successful upload grants server-side code execution in the WordPress host context.

The record

CVE
CVE-2021-47933
Published
May 10, 2026
Updated
May 10, 2026
Vendor
FluxBuilder
Product
MStore API
Classifications
CWE-306, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 10, 2026CVE publishedPublication date reported by the CVE source.
  2. May 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=2.0.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FluxBuilder · MStore APIversion=2.0.6

Published CVSS scores

9.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
9.8VulnCheckCVSS: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 exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1190Exploit Public-Facing Application

Public exploit references

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

Technologies

Your stack

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Your stack

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