CVE-2026-97296 in Gravity Forms Plugin
Summary
by MITRE • 10/16/2026
Deserialization of Untrusted Data vulnerability in Rocketgenius, Inc Gravity Forms gravityforms allows Object Injection.This issue affects Gravity Forms: from n/a before 3.1.1.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 10/16/2026
The identified vulnerability represents a critical security flaw within the Gravity Forms plugin for WordPress, specifically affecting versions prior to release 3.1.1. This issue is classified as an Unrestricted Deserialization of User-Controlled Data, which falls under the Common Weakness Enumeration (CWE) category CWE-502. The core technical failure lies in the application's handling of serialized PHP objects received from untrusted sources without adequate validation or sanitization mechanisms. In a typical WordPress environment, Gravity Forms processes form submissions and may serialize data for storage, caching, or internal processing. When an attacker can influence the content being deserialized, they gain the ability to inject malicious object instances into the application's execution context. This specific type of vulnerability is often referred to as PHP Object Injection, where the attacker crafts a serialized string that corresponds to a class existing within the WordPress core, Gravity Forms itself, or any other loaded plugin or theme.
The operational impact of this vulnerability is severe and potentially catastrophic for the affected system. By successfully exploiting the deserialization flaw, an authenticated attacker with minimal privileges, such as a subscriber-level user who can submit forms, could achieve Remote Code Execution (RCE). The attack vector typically involves constructing a serialized payload that instantiates a class with magic methods like __wakeup(), __destruct(), or __toString(). These methods are automatically invoked during the deserialization process. If the injected object interacts with sensitive system functions, file operations, or database queries in an unintended manner, it allows the attacker to execute arbitrary commands on the server hosting the WordPress instance. This can lead to complete compromise of the web application, unauthorized access to confidential data stored within the database, and potentially further lateral movement into the underlying network infrastructure if the server is not properly isolated.
From a threat intelligence perspective, this vulnerability aligns with MITRE ATT&CK techniques related to Command and Scripting Interpreter execution via deserialization flaws. Attackers often leverage such weaknesses as part of an initial access or privilege escalation strategy within web application attacks. The lack of strict type checking or allow-listing for classes permitted during deserialization is the primary enabler of this exploit chain. Without proper safeguards, the PHP runtime blindly trusts the serialized data structure, allowing external inputs to dictate internal object states and behaviors. This undermines the integrity and confidentiality guarantees expected from secure software design principles.
Mitigation strategies must be implemented immediately by administrators running affected versions of Gravity Forms. The primary and most effective remediation is to upgrade the plugin to version 3.1.1 or later, where this vulnerability has been addressed through improved input validation and stricter deserialization controls. Until an update can be applied, temporary mitigations include restricting form submission capabilities to trusted users only, if feasible within the site's operational requirements. Additionally, implementing a Web Application Firewall (WAF) with rules specifically designed to detect and block suspicious serialized payloads or known exploit signatures related to PHP object injection can provide a layer of defense in depth. It is also advisable to review server-side configurations to ensure that dangerous functions are disabled where possible and that error reporting does not leak sensitive stack trace information during exploitation attempts, thereby reducing the attack surface available to potential adversaries.