CVE-2026-103039

The Gravity Forms plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.1.2 via a Post Custom Field whose input type is List. This is due to GFFormsModel::create_post() passing the submitted value to WordPress' unrestricted global maybe_unserialize() rather than the plugin's own hardened GFCommon::maybe_unserialize(), which was added in 3.1.1 and passes allowed_classes => false precisely to prevent object instantiation. Where the field has a content template enabled, the submitted row reaches that call verbatim. This makes it possible for unauthenticated attackers to inject a PHP object into post meta. No PHP Object Injection gadget chain is present in the plugin itself; however, if a gadget chain is present via an additional plugin or theme, it could allow the attacker to perform actions such as remote code execution. Where the custom field is mapped to the protected _wp_page_template meta key, WordPress itself supplies the chain: validate_file() accepts non-scalars, WP_Theme::__toString() then resolves an attacker-controlled path, and on hosts with a readable PEAR install and register_argc_argv enabled this yields remote code execution.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://docs.gravityforms.com/
https://www.wordfence.com/threat-intel/vulnerabilities/id/ec1fba15-81e5-42e3-9154-1978c3f81b26?source=cve

Configurations

No configuration.

History

30 Oct 2026, 07:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-30 07:16

Updated : 2026-10-30 16:17

NVD link : CVE-2026-103039

Mitre link : CVE-2026-103039

CVE.ORG link : CVE-2026-103039

JSON object : View

Products Affected

No product.

CWE

CWE-502

Deserialization of Untrusted Data

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