CVE-2026-15984

High

Description

The QuickCal plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Custom Field Parameters in all versions up to, and including, 1.0.20 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. The nonce guarding the unauthenticated booked_add_appt AJAX action is publicly embedded on any page rendering the booking calendar shortcode, making it trivially obtainable by unauthenticated attackers without any prior account or privilege.

SeverityHigh
CVSS7.2
Exploit probability—
ProductQuickCal
PublishedSep 5, 2026
First seenSep 5, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
Themovation QuickCalv ≤ 1.0.20—

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