CVE-2026-118076 in Pay Plugin
Summary
by MITRE • 10/29/2026
Contributor PHP Object Injection in Frisbii Pay <= 1.8.19 versions.
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Analysis
by VulDB Data Team • 10/29/2026
The vulnerability identified as Contributor PHP Object Injection in the Frisbii Pay plugin, affecting versions up to and including 1.8.19, represents a critical security flaw rooted in improper handling of user-supplied input within the WordPress ecosystem. This specific type of attack leverages the PHP serialization mechanism, which is frequently used by plugins for storing complex data structures such as arrays or objects into transient storage options like wp_options or post meta fields. When an application deserializes this data without validating its integrity or source, it opens a pathway for attackers to inject malicious serialized strings that instantiate arbitrary classes with controlled properties. In the context of Frisbii Pay, which handles payment processing and financial transactions, such an injection can have severe consequences beyond typical information disclosure, potentially leading to full server compromise or manipulation of transactional data.
The technical mechanism behind this vulnerability typically involves a lack of strict type checking or whitelisting when unserializing user-controlled parameters. An attacker with contributor-level access or lower, which is often easily attainable through registration on public-facing WordPress sites, can manipulate input fields that are subsequently passed to PHP's unserialize function. By crafting a payload containing a gadget chain—a sequence of object instantiations and method calls—the attacker can trigger unintended side effects during the deserialization process. These gadgets may interact with other parts of the application or even core PHP functions, allowing for remote code execution, denial of service conditions by exhausting system resources, or unauthorized access to sensitive administrative functionalities that should be restricted to higher-privileged roles.
From an operational perspective, this vulnerability poses a significant risk to both site administrators and their customers. If exploited successfully, it can allow malicious actors to bypass authentication mechanisms, escalate privileges from contributor to administrator, or inject backdoors into the website's codebase. Given that Frisbii Pay deals with payment gateways and financial data, any compromise could lead to direct monetary loss through manipulated transactions, theft of customer credit card information if stored improperly, or reputational damage due to a breach of trust. Furthermore, attackers might use the compromised server as part of a larger botnet for distributed denial-of-service attacks or phishing campaigns, leveraging the site's credibility to deceive other users.
This vulnerability aligns with Common Weakness Enumeration (CWE) ID 502, which describes Deserialization of Untrusted Data. It also maps closely to MITRE ATT&CK techniques related to Initial Access and Privilege Escalation, specifically those involving web application attacks where attackers exploit input validation failures to gain footholds within the system environment. The presence of such a flaw indicates a gap in secure coding practices regarding the handling of serialized data, emphasizing the need for rigorous input sanitization and output encoding strategies.
To mitigate this risk, immediate action is required by updating the Frisbii Pay plugin to version 1.8.20 or later, where these deserialization issues have been addressed through stricter validation protocols and potentially the removal of unsafe unserialization calls in favor of safer alternatives like JSON decoding for data interchange. Administrators should also enforce principle of least privilege by ensuring that only trusted users with administrator-level access can modify critical plugin settings if possible. Implementing a Web Application Firewall (WAF) capable of detecting anomalous serialized payloads can provide an additional layer of defense against exploitation attempts while patches are being applied. Regular security audits and code reviews focusing on deserialization practices are essential to prevent similar vulnerabilities in future updates or other plugins used within the same environment.