CVE-2026-96573

Appointment Hour Booking <= 1.5.97 - Unauthenticated Stored DOM-Based Cross-Site Scripting via Booking Form Single-Line Field via Schedule Calendar List Renderer

2026-09-30 20:09
Zackary Loevseth

Strategic Overview

Status
Patched in 1.5.98
Affected Plugin
Appointment Hour Booking – Booking Calendar
Affected Version
<= 1.5.97
CVSS
7.2High
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2026-96573
View all Appointment Hour Booking – Booking Calendar vulnerabilities

At a glance

CVE-2026-96573 is a high-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Appointment Hour Booking WordPress plugin, affecting versions <= 1.5.97. It carries a CVSS score of 7.2 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 1.5.98; sites on affected versions should update now. Disclosed September 2026, reported by Zackary Loevseth.

Vulnerability Overview

The Appointment Hour Booking – Booking Calendar plugin for WordPress is vulnerable to Stored DOM-Based Cross-Site Scripting via Booking Form Single-Line Field via Schedule Calendar List Renderer in all versions up to, and including, 1.5.97 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires the 'list_readmore_numberofwords' Other Parameters setting to be configured with a positive integer value; the default value of 0 bypasses the decode-and-truncate branch entirely and is not exploitable through this sink.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Appointment Hour Booking <= 1.5.97 carries this weakness at list_readmore_numberofwords, and reaching it takes no account at all. 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 Appointment Hour Booking the fix is 1.5.98: builds <= 1.5.97 are affected, anything from 1.5.98 onward is not.

Remediation

Update to version 1.5.98, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Appointment Hour Booking 1.5.98 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-96573https://www.wordfence.com/threat-intel/vulnerabilities/id/3044e60f-b930-42db-ba5d-656e71b84226https://nvd.nist.gov/vuln/detail/CVE-2026-96573

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C