XSS in Xootix Waitlist Woocommerce ( Back In Stock Notifier )

CVE-2026-77188

The Waitlist Woocommerce ( Back in stock notifier ) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'type' Shortcode Attribute in all versions up to, and including, 2.9.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The wp_kses_post filter applied on contributor post save does not prevent this vulnerability because shortcode attribute values are not HTML and pass through kses unchanged; the payload is materialized only at render time when the shortcode is expanded.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (9.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 9.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-77188?
CVE-2026-77188 is a medium-severity vulnerability in Xootix Waitlist Woocommerce ( Back In Stock Notifier ), classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-10-28.
How severe is CVE-2026-77188?
Medium severity. CVSS v3 base score is 6.4 out of 10.