CVE-2023-23656Network attack vector

Unauthenticated arbitrary file upload

Published Mar 26, 2024 · Updated Apr 28, 2026

Unrestricted file upload in MainWP File Uploader Extension 4.1 and earlier allows remote attackers to place arbitrary files on managed sites. Public advisories do not identify the upload handler or disclose why an unauthenticated request reaches the extension's file-placement workflow. No authentication is required; uploaded PHP can execute as server-side code when the destination web server permits it.

CVSS severity10.0
Critical
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unrestricted file upload in MainWP File Uploader Extension 4.1 and earlier allows remote attackers to place arbitrary files on managed sites. Public advisories do not identify the upload handler or disclose why an unauthenticated request reaches the extension's file-placement workflow. No authentication is required; uploaded PHP can execute as server-side code when the destination web server permits it.

The record

CVE
CVE-2023-23656
Published
Mar 26, 2024
Updated
Apr 28, 2026
Vendor
MainWP
Product
MainWP File Uploader Extension
Classifications
CWE-434, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 26, 2024CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 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 <=4.1
  2. Affected versionversion=n/a <=4.1 changes=[{"at":"4.1.1","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MainWP · MainWP File Uploader Extensionversion=0 <=4.1; version=n/a <=4.1 changes=[{"at":"4.1.1","status":"unaffected"}]

Published CVSS scores

10.0PatchstackCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
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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