CVE-2026-14216 in Booking for Appointments and Events Calendar Plugin
Summary
by MITRE • 08/26/2026
The Booking for Appointments and Events Calendar WordPress plugin before 2.4.7 does not require authentication before processing its pending notification queue, allowing an unauthenticated user to force the dispatch of queued notifications and integration callbacks.
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Analysis
by VulDB Data Team • 08/26/2026
The vulnerability identified in the Booking for Appointments and Events Calendar WordPress plugin prior to version 2.4.7 represents a critical failure in access control mechanisms within the application's background processing logic. Specifically, the flaw resides in how the plugin handles its pending notification queue and integration callback dispatching processes. In secure software architecture, operations that trigger external communications or state changes should be protected by authentication checks to ensure that only authorized administrators can initiate such actions. However, this implementation allows any user with network access to interact directly with these endpoints without providing valid credentials or session tokens. This lack of enforcement creates a significant security gap where the application fails to verify the identity and privileges of the requester before executing sensitive background tasks.
From a technical perspective, the core issue is an improper authorization check on server-side functions responsible for processing queued notifications. When a request targets these specific endpoints, the plugin proceeds to iterate through pending items in its queue and dispatches them immediately. This behavior enables unauthenticated actors to force the execution of code that was intended to run only under administrative context or during legitimate user interactions. The ability to trigger this process remotely means an attacker can manipulate the application's state by injecting requests into the notification pipeline, potentially causing unintended side effects such as spamming users with emails, triggering third-party integrations unnecessarily, or exhausting server resources through rapid-fire processing of queued items.
The operational impact of this vulnerability extends beyond simple denial of service scenarios. By forcing the dispatch of notifications and integration callbacks, an attacker can disrupt business operations associated with appointment bookings and event management systems built on WordPress. For instance, if the plugin integrates with payment gateways or email marketing services, unauthorized triggers could lead to incorrect billing events, unwanted customer communications, or data leakage through exposed callback parameters. Furthermore, this flaw aligns with CWE-862, which describes a missing authorization check, and is relevant to MITRE ATT&CK technique T1059, specifically the sub-category of command and script interpretation via web applications if the callbacks allow for further exploitation chains. The vulnerability essentially turns background administrative functions into publicly accessible tools that can be abused by malicious actors without any barrier to entry.
Mitigation strategies must focus on immediate patching and defensive configuration adjustments until an update is applied. Administrators should upgrade the Booking for Appointments and Events Calendar plugin to version 2.4.7 or later, where this authorization flaw has been addressed by implementing proper access controls that verify user permissions before processing any pending notifications. In environments where upgrading is not immediately feasible, network-level mitigations such as Web Application Firewalls can be configured to block requests targeting the specific endpoints associated with the notification queue and callback dispatching functions. Additionally, restricting access to WordPress admin-ajax.php or similar internal API handlers via IP whitelisting for administrative IPs can provide a temporary layer of defense against unauthenticated exploitation attempts. Regular security audits and monitoring of server logs for unusual spikes in background task executions are also recommended to detect potential abuse of this vulnerability early.