CVE-2025-23921Known exploitationNetwork attack vector

Unauthenticated code execution via unrestricted file upload

Published Jan 22, 2025 · Updated May 11, 2026

Unrestricted file upload in sh1zen Multi Uploader for Gravity Forms 1.1.3 and earlier allows remote attackers to place executable web shells. The unauthenticated gf_page=upload endpoint accepts crafted multipart/form-data containing a traversal-bearing gform_unique_id and a disguised .phtml payload. Successful exploitation requires the upload route to be exposed and executes server-side code with the web server's privileges.

CVSS severity9.0
Critical
EPSS probability0.53%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unrestricted file upload in sh1zen Multi Uploader for Gravity Forms 1.1.3 and earlier allows remote attackers to place executable web shells. The unauthenticated gf_page=upload endpoint accepts crafted multipart/form-data containing a traversal-bearing gform_unique_id and a disguised .phtml payload. Successful exploitation requires the upload route to be exposed and executes server-side code with the web server's privileges.

The record

CVE
CVE-2025-23921
Published
Jan 22, 2025
Updated
May 11, 2026
Vendor
sh1zen
Product
Multi Uploader for Gravity Forms
Classifications
CWE-434, CAPEC-650, T1505.003, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 1, 2024Exploitation reportedTXOne telemetry exploitation attempts
  2. Jan 22, 2025CVE publishedPublication date reported by the CVE source.
  3. May 11, 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 <=1.1.3 changes=[{"at":"1.1.5","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

sh1zen · Multi Uploader for Gravity Formsversion=0 <=1.1.3 changes=[{"at":"1.1.5","status":"unaffected"}]

Published CVSS scores

9.0PatchstackCVSS:3.1/AV:N/AC:H/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 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-434Unrestricted Upload of File with Dangerous Type
CAPEC-650Upload a Web Shell to a Web Server
T1505.003Web Shell
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.

Reported exploitation

Technologies

Your stack

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Your stack

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