CVE-2026-59539 in Paid Member Subscriptions Plugin
Summary
by MITRE • 07/27/2026
Subscriber Insecure Direct Object References (IDOR) in Paid Member Subscriptions <= 3.0.7 versions.
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Analysis
by VulDB Data Team • 07/27/2026
Insecure Direct Object References represent a critical vulnerability class that allows unauthorized access to resources through manipulation of object references such as database keys, file paths, or API endpoints. This particular vulnerability affects subscriber paid member subscriptions software versions up to and including 3.0.7, where the system fails to properly validate user permissions when processing requests for subscription-related data. The flaw stems from inadequate input validation mechanisms that permit any authenticated user to access subscription details of other users by simply modifying object identifiers in API calls or web requests.
The technical implementation of this vulnerability occurs at the application level where direct object references are used without proper authorization checks. When a user accesses subscription information, the system typically relies on parameters such as user IDs or subscription IDs passed directly from client to server without verifying whether the requesting user has legitimate access rights to those specific resources. This creates an opportunity for privilege escalation attacks where malicious actors can iterate through different object identifiers to discover and access other users' subscription data, including payment information, billing details, and membership status.
The operational impact of this vulnerability extends beyond simple data exposure to encompass potential financial fraud, privacy violations, and regulatory compliance issues. Attackers could exploit this weakness to view competing users' subscription details, potentially leading to identity theft, fraudulent transactions, or targeted attacks against premium subscribers. The vulnerability aligns with CWE-639 which specifically addresses authorization flaws allowing access to unauthorized resources through direct object references. From an adversarial perspective, this represents a low-effort, high-reward attack vector that fits within the ATT&CK framework under privilege escalation techniques where attackers seek to expand their access beyond initially granted permissions.
Mitigation strategies should focus on implementing robust access control mechanisms including proper authorization checks at every point where direct object references are processed. The system must validate that each request originates from an authorized user with legitimate access rights to the requested resource, typically through user session validation, role-based access controls, or explicit permission checking against database records. Additionally, organizations should implement parameterized queries and input sanitization to prevent manipulation of object identifiers, while also considering the implementation of random or encrypted identifiers that cannot be easily guessed or enumerated by attackers.
The vulnerability demonstrates the critical importance of defense in depth approaches to application security, where multiple layers of protection including authentication, authorization, and input validation work together to prevent unauthorized access. Organizations should conduct regular security assessments focusing on object reference handling, implement automated testing for IDOR vulnerabilities during development cycles, and maintain up-to-date monitoring systems to detect suspicious access patterns. The remediation process requires immediate patching of affected versions along with comprehensive code review to identify all potential direct object references that may require authorization validation. Furthermore, implementing proper logging and alerting mechanisms around subscription access attempts can help detect exploitation attempts and provide evidence for forensic analysis when incidents occur.