CVE-2023-6133Network attack vector

Authenticated arbitrary file upload via MIME blacklist bypass

Published Nov 15, 2023 · Updated Apr 8, 2026

Arbitrary file upload in WPMU DEV Forminator 1.27.0 and earlier allows remote authenticated users to upload arbitrary files via crafted MIME types. The forminator_allowed_mime_types function relies on insufficient blacklist filtering, permitting dangerous file types to reach server storage. Administrator-level capabilities are required, and the advisory states that htaccess prevents remote code execution.

CVSS severity4.9
Medium
EPSS probability0.86%
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 WPMU DEV Forminator 1.27.0 and earlier allows remote authenticated users to upload arbitrary files via crafted MIME types. The forminator_allowed_mime_types function relies on insufficient blacklist filtering, permitting dangerous file types to reach server storage. Administrator-level capabilities are required, and the advisory states that htaccess prevents remote code execution.

The record

CVE
CVE-2023-6133
Published
Nov 15, 2023
Updated
Apr 8, 2026
Vendor
WPMU DEV
Product
Forminator
Classifications
CWE-434, T1190
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Nov 15, 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

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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=0 <=1.27.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

WPMU DEV · Forminatorversion=0 <=1.27.0

Published CVSS scores

4.9NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
6.6WordfenceCVSS:3.1/AV:N/AC:H/PR:H/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1190Exploit Public-Facing Application

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.

Technologies

Your stack

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Your stack

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