CVE-2026-42691 in EventPrime Event Calendar Management Plugin
Summary
by MITRE • 10/29/2026
Authorization Bypass Through User-Controlled Key vulnerability in EventPrime EventPrime eventprime-event-calendar-management allows Privilege Abuse.This issue affects EventPrime: from n/a through 4.3.6.0.
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Analysis
by VulDB Data Team • 10/29/2026
The identified vulnerability represents a critical authorization bypass within the EventPrime event calendar management system, specifically classified as an Authorization Bypass Through User-Controlled Key flaw. This security defect allows for privilege abuse by enabling unauthorized actors to manipulate internal identifiers or keys associated with user sessions and resource access controls. In typical web application architectures, such vulnerabilities arise when the server relies on client-supplied data, such as session tokens, database IDs, or configuration parameters, without performing adequate validation against the authenticated user's actual permissions. By altering these controlled keys, an attacker can escalate their privileges from a standard user role to that of an administrator or gain access to sensitive resources belonging to other users or system components. This type of flaw is fundamentally rooted in insecure direct object references and improper privilege management, aligning with CWE-284 Improper Access Control and CWE-639 Authorization Bypass Through User-Controlled Key as defined by the Common Weakness Enumeration standards.
From a technical perspective, this vulnerability likely manifests when EventPrime processes requests related to event creation, modification, or deletion without strictly binding the operation to the authenticated user's identity in the backend logic. If the application uses predictable identifiers for events or administrative functions and fails to verify that the requesting user has ownership of or explicit permission for those specific entities, an attacker can simply substitute a different identifier in their HTTP requests. This allows them to perform actions such as viewing private event details, modifying public schedules without authorization, or potentially executing administrative commands if the key manipulation extends to system-level configurations. The impact is severe because it undermines the core integrity of the access control model, effectively rendering authentication mechanisms insufficient for ensuring data confidentiality and operational integrity within the calendar management platform.
The operational impact of this vulnerability is significant for organizations relying on EventPrime for scheduling and coordination. An attacker exploiting this flaw could disrupt business operations by altering or deleting critical event information, leading to logistical failures and reputational damage. Furthermore, if administrative privileges are compromised through key manipulation, the attacker gains full control over the application's configuration, potentially allowing them to inject malicious scripts, exfiltrate user data including personal identifiable information stored in event descriptions or attendee lists, or disable security logging features. This aligns with several tactics within the MITRE ATT&CK framework, particularly T1078 Valid Accounts for initial access if combined with credential theft, and T1068 Exploitation for Privilege Escalation to gain higher-level system control. The ability to abuse privileges means that even users with low-level access can cause widespread disruption or data breaches without needing complex exploitation techniques beyond simple parameter tampering.
Mitigation strategies must focus on implementing robust server-side validation and enforcing strict object-level authorization checks. Developers should ensure that every request involving sensitive resources verifies the relationship between the authenticated user session and the target resource ID, rejecting any requests where this association is invalid or unauthorized. It is essential to avoid using sequential or predictable identifiers for critical operations; instead, employing cryptographically secure random identifiers can reduce the risk of enumeration attacks that often accompany key manipulation vulnerabilities. Additionally, implementing role-based access control (RBAC) with explicit allow-lists rather than deny-lists ensures that only permitted actions are executed based on verified user roles. Regular security audits and penetration testing focused on authorization logic should be conducted to identify similar flaws across other modules within the EventPrime ecosystem. For users of versions up through 4.3.6.0, applying vendor-provided patches is the primary remediation step, as these updates typically include fixes for input validation and access control enforcement mechanisms that address this specific privilege abuse vector.