Unrestricted File UploadWeakness · CWE-434

CVE-2025-12528

HIGH · 8.1 CVSS v3.1 Published 2025-11-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
90/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The Pie Forms for WP plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 1.6 via the format_classic function. This is due to insufficient file type validation where the validate_classic method validates file extensions and sets error messages but does not prevent the file upload process from continuing. This makes it possible for unauthenticated attackers to upload files with dangerous extensions such as PHP, which makes remote code execution possible. In order to exploit this vulnerability, the attacker needs to guess the directory in which the file is placed (which is a somewhat predictable hash). In addition to that, the file name is generated using a secure hash method, limiting the exploitability of this vulnerability.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The Pie Forms for WP plugin's format_classic function has a logic flaw where the validate_classic method checks file extensions and sets error messages but does NOT actually stop the file upload from completing. This allows unauthenticated attackers to upload executable files like PHP despite validation warnings, enabling potential remote code execution.

MitigationUpdate to patched version when available; until then, disable or restrict the file upload feature in Pie Forms, and consider web application firewall rules to block PHP file uploads.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Pie Forms plugin is installed
    Navigate to WordPress admin > Plugins and verify 'Pie Forms' is listed as an active or installed plugin
    Affected if Pie Forms plugin is installed and active on the WordPress site
  2. Identify installed Pie Forms version
    In WordPress admin > Plugins, find Pie Forms and note the version number displayed, or check the plugin header in wp-content/plugins/pie-forms-for-wp/pie-forms-for-wp.php
    Affected if The installed version is any version prior to the patched release (version numbers should be compared against the vendor's security advisory once available)
  3. Check if file upload field is enabled in any form
    Navigate to Pie Forms > All Forms, open each form, and look for a 'File Upload' field type in the form builder; or inspect the database table wp_postmeta for posts with post_type='pie-forms' and meta_key containing 'file-upload' fields
    Affected if At least one form on the site contains a File Upload field and is published or active
  4. Verify the vulnerable validate_classic function exists
    Access the site via FTP or file manager, locate wp-content/plugins/pie-forms-for-wp/includes/fields/class-pie-fields-classic.php and search for the 'validate_classic' function; examine if it sets error messages but lacks a return statement to halt execution after validation failures
    Affected if The plugin code contains the validate_classic function without proper upload termination logic after validation errors
  5. Test file upload with executable extension
    Using the form's front-end file upload functionality (if publicly accessible), attempt to upload a file with a .php extension and observe whether an error message appears but the file is still processed or stored
    Affected if The upload returns a validation warning message but the file is still accepted and stored on the server
  6. Inspect uploaded files directory
    Check the wp-content/uploads/pie-forms/ directory (or configured upload path) for any files with executable extensions such as .php, .php5, .phtml, or .exe
    Affected if Executable files exist in the Pie Forms upload directory, indicating a successful bypass of the validation logic

The environment is affected if Pie Forms plugin is installed with any form that has an active File Upload field, and the plugin version predates the vendor's patched release, as the validate_classic function allows PHP files to be uploaded despite showing validation warnings.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update to patched version when available; until then, disable or restrict the file upload feature in Pie Forms, and consider web application firewall rules to block PHP file uploads.

Recommended fix Moderate confidence

Update to the latest version of Pie Forms for WP (version higher than 1.6, which contains the security fix)

  1. Log in to the WordPress admin dashboard
  2. Navigate to Plugins > Installed Plugins
  3. Find 'Pie Forms for WP' in the list
  4. If an update is available, click 'Update Now' to update to the latest version
  5. Alternatively, navigate to Dashboard > Updates and update the plugin from there
  6. After updating, verify the new version number reflects the patched release
Caveat Review the plugin's changelog for any feature changes or deprecations before updating in production environments

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-12528 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data