CVE-2026-15984
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.
What this means for your business
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.2% chance of attack attempts being seen in the next 30 days, ranking above 8% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Scoring
- CVSS
- 7.2 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N- Weakness
- CWE-79
- Assigned by
- security@wordfence.com
Dates
- Published
- 2026-09-05
- Last modified
- 2026-09-08
- Sources
- NVD