XSS in Quadlayers Social Chat – Click To App Button

CVE-2026-18404

The Social Chat – Click To Chat App Button plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'consent_message' JSON Attribute in .qlwapp data-box in all versions up to, and including, 8.6.2 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 exploit requires no user interaction beyond page load, as setting auto_open and consent_enabled to 'yes' in the injected data-box JSON causes the consent box — and the embedded script — to execute immediately on page load.

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 (9.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 9.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-18404: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-18404?
CVE-2026-18404 is a medium-severity vulnerability in Quadlayers Social Chat – Click To App Button, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-09-05.
How severe is CVE-2026-18404?
Medium severity. CVSS v3 base score is 6.4 out of 10.