CVE-2026-96347 in Bookly Plugin
Summary
by MITRE • 09/30/2026
Subscriber Insecure Direct Object References (IDOR) in Bookly <= 28.2 versions.
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Analysis
by VulDB Data Team • 09/30/2026
The vulnerability identified as an insecure direct object reference within the Bookly plugin for WordPress, affecting versions up to and including 28.2, represents a critical authentication bypass mechanism that allows unauthorized access to sensitive subscriber data. This flaw stems from the application's failure to implement proper authorization checks when processing requests related to user-specific resources. In secure software design, every request accessing a specific object or resource must verify that the authenticated user has permission to view or modify that particular item. However, in this instance, the backend logic relies on predictable identifiers such as sequential numeric IDs passed directly via HTTP parameters without validating whether these IDs belong to the requesting user's account. This architectural oversight creates a classic insecure direct object reference scenario where an attacker can manipulate input variables to access data belonging to other subscribers.
From a technical perspective, this vulnerability is categorized under CWE-639, which defines Insecure Direct Object References as flaws occurring when an application exposes a reference to an internal implementation object such as a file, directory, or database key without proper authorization checks. When a subscriber logs into the Bookly dashboard, they are typically issued session tokens that authenticate their identity but do not necessarily restrict access to other users' appointment histories, personal details, or payment records if those resources are accessed via direct URL manipulation or API calls using arbitrary IDs. An attacker who has obtained valid credentials for even a low-privilege subscriber account can iterate through sequential ID values in the request parameters. By systematically changing these identifiers, the attacker can retrieve information associated with different user accounts, effectively bypassing any intended isolation between users within the same system instance.
The operational impact of this vulnerability is severe due to the sensitive nature of the data involved. Bookly manages appointment scheduling for businesses and professionals, meaning it stores personally identifiable information including names, email addresses, phone numbers, and potentially payment details or medical history depending on the industry context. Unauthorized access to this database can lead to significant privacy violations, identity theft, and financial fraud against affected subscribers. Furthermore, because the vulnerability allows data exfiltration without requiring administrative privileges, a compromised low-level account serves as an entry point for broader reconnaissance within the organization's digital infrastructure. This aligns with MITRE ATT&CK technique T1078, Valid Accounts, where attackers leverage legitimate credentials to move laterally or extract sensitive information from internal systems that are not intended for public access.
Mitigation strategies must address both immediate remediation and long-term architectural improvements. The primary solution is to upgrade the Bookly plugin to a version newer than 28.2, as developers have likely implemented proper authorization checks in subsequent releases to validate user ownership of requested resources before returning data. For organizations unable to patch immediately due to compatibility constraints or deployment cycles, temporary mitigations include implementing strict input validation on all endpoints that accept object identifiers and ensuring that server-side logic explicitly verifies the relationship between the authenticated session ID and the resource ID being accessed. Additionally, deploying a Web Application Firewall with rules designed to detect sequential enumeration attacks can provide an additional layer of defense by monitoring for patterns indicative of automated IDOR exploitation attempts. Regular security audits focusing on authorization controls are essential to prevent similar flaws from persisting in custom integrations or third-party extensions that interact with the core booking system.