WP Booking System <= 2.1.0.3 - Missing Authorization to Authenticated (Subscriber+) Privilege Escalation via 'user_permission' Parameter via Cross-Form Nonce Reuse
Strategic Overview
- Status
- Patched in 2.1.0.4
- Affected Plugin
- WP Booking System – Booking Calendar
- Affected Version
<= 2.1.0.3- CVSS
- 6.8Medium
- Weakness type
- CWE-862 · Missing Authorization
- CVE
CVE-2026-109369
At a glance
CVE-2026-109369 is a medium-severity Missing Authorization vulnerability in the WP Booking System WordPress plugin, affecting versions <= 2.1.0.3. It carries a CVSS score of 6.8 (reachable over the network; high confidentiality, integrity impact). Exploitation requires an authenticated account at Subscriber level or above. The issue is fixed in version 2.1.0.4; sites on affected versions should update now. Disclosed October 2026, reported by Wordfence PRISM.
Vulnerability Overview
The WP Booking System – Booking Calendar plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 2.1.0.3 This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with subscriber-level access and above, to grant themselves and arbitrary other users edit access to every booking form on the site by overwriting the user_permission meta that governs the plugin's own access-control list. Exploitation requires the attacker to have already been delegated edit rights on at least one booking form, as this delegation both downgrades the submenu capability to 'read' (making the edit page accessible) and allows them to harvest a valid wpbs_edit_form nonce that will pass validation against any other form_id.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity.
CWE-862: Missing Authorization
WP Booking System <= 2.1.0.3 carries this weakness at read, and reaching it takes an account at Subscriber level or above. A missing authorization check means a function is reachable by anyone who can reach the endpoint, because the code never asks whether the caller is allowed to perform the action.
Any user who can reach the endpoint gets to run an action reserved for higher-privileged roles, from reading protected data to changing settings or content. For WP Booking System the fix is 2.1.0.4: builds <= 2.1.0.3 are affected, anything from 2.1.0.4 onward is not.
Remediation
Update to version 2.1.0.4, or a newer patched version
How does WordSec protect against this?
Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: WP Booking System 2.1.0.4 closes this, and updating the plugin is the step that ends it.
- Login Security
- Alerts
External References
Related records
Same weakness class
- 7.5CVE-2026-108123: WP Booking System Unauthenticated Info Disclosure
CVE-2026-108123 - 6.5CVE-2026-109368: WP Booking System Authenticated (Subscriber+) Info
CVE-2026-109368 - 4.3CVE-2024-50425: WP Booking System <= 2.0.19.10 Missing Authorization
CVE-2024-50425 - 4.3CVE-2023-49758: WP Booking System <= 2.0.19.2 Missing Authorization
CVE-2023-49758
Other vulnerabilities in WP Booking System – Booking Calendar
- 9.8CVE-2019-12239: WP Booking System Free version < 1.5.2 CSRF
CVE-2019-12239 - 7.2CVE-2026-107126: WP Booking System – Booking Calendar Stored XSS
CVE-2026-107126 - 6.5CVE-2026-107712: WP Booking System <= 2.1.0.1 SQL Injection
CVE-2026-107712 - 6.1CVE-2024-8797: WP Booking System – Booking Calendar Reflected XSS
CVE-2024-8797 - 6.1CVE-2021-25061: WP Booking System – Booking Calendar Reflected XSS
CVE-2021-25061 - 6.1CVE-2017-2168: WP Booking System – Booking Calendar < 1.4 XSS
CVE-2017-2168 - 5.3CVE-2025-68515: WP Booking System Information Exposure
CVE-2025-68515 - 4.9CVE-2026-111178: WP Booking System <= 2.1.0.1 SQL Injection
CVE-2026-111178
Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C