Bookly <= 21.7 - Authenticated (Admin+) Stored Cross-Site Scripting
Strategic Overview
- Status
- Patched in 21.8
- Affected Plugin
- Online Scheduling and Appointment Booking System – Bookly
- Affected Version
21.7- CVSS
- 4.0Medium
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2023-1159
At a glance
CVE-2023-1159 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Online Scheduling and Appointment Booking System WordPress plugin, affecting versions 21.7. It carries a CVSS score of 4.0 (reachable over the network). Exploitation requires an authenticated account at Admin level or above. The issue is fixed in version 21.8; sites on affected versions should update now. Disclosed June 2023, reported by Vinay Kumar.
Vulnerability Overview
The Bookly plugin for WordPress is vulnerable to Stored Cross-Site Scripting via service titles in versions up to, and including, 21.5 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers with administrative privileges to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.
Technical Analysis
The vector marks this flaw as remotely reachable over the network.
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Reaching this weakness in Online Scheduling and Appointment Booking System 21.7 takes an account at Admin level or above. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.
Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Online Scheduling and Appointment Booking System the fix is 21.8: builds 21.7 are affected, anything from 21.8 onward is not.
Remediation
Update to version 21.8, or a newer patched version
How does WordSec protect against this?
An attacker needs Admin access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Online Scheduling and Appointment Booking System 21.8 closes this, and updating the plugin is the step that ends it.
- Firewall
- Alerts
External References
Related records
Same weakness class
- 7.2CVE-2026-13424: Online Scheduling and Appointment… Stored XSS
CVE-2026-13424 - 7.2CVE-2026-61944: Online Scheduling and Appointment… Stored XSS
CVE-2026-61944 - 7.2CVE-2026-5513: Online Scheduling and Appointment… Stored XSS
CVE-2026-5513 - 7.2CVE-2023-1172: Bookly <= 21.5 Stored Cross-Site Scripting
CVE-2023-1172
Other vulnerabilities in Online Scheduling and Appointment Booking System – Bookly
- 8.1CVE-2023-26526: Bookly <= 21.7.1 Arbitrary File Deletion
CVE-2023-26526 - 7.5CVE-2026-13395: Online Scheduling and Appointment… SQL Injection
CVE-2026-13395 - 7.5CVE-2026-14516: Online Scheduling and Appointment… SQL Injection
CVE-2026-14516 - 7.5CVE-2026-61949: Online Scheduling and Appointment… SQL Injection
CVE-2026-61949 - 7.2CVE-2018-6891: WordPress Online Booking… XSS
CVE-2018-6891 - 6.6CVE-2023-4691: Bookly <= 22.3.1 SQL Injection
CVE-2023-4691 - 6.4CVE-2024-5584: WordPress Online Booking… Stored XSS
CVE-2024-5584 - 6.1CVE-2026-32540: Online Scheduling and Appointment… Reflected XSS
CVE-2026-32540
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