XSS in Fernandot Vigilant – 100% Free Security Suite: Firewall, 2fa, Login, Headers, Scanner…

CVE-2026-81754

The Vigilant – 100% Free Security Suite: Firewall, 2FA, Login, Headers, Scanner… plugin for WordPress is vulnerable to Stored Cross-Site Scripting via User-Agent Header in all versions up to, and including, 2.10.2 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 malicious payload is delivered passively by any unauthenticated visitor who triggers a failed login attempt with a crafted User-Agent header, requiring no further interaction from the attacker once stored.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (35.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 35.9% 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-2026-81754: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-81754?
CVE-2026-81754 is a high-severity vulnerability in Fernandot Vigilant – 100% Free Security Suite: Firewall, 2fa, Login, Headers, Scanner…, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-09-11.
How severe is CVE-2026-81754?
High severity. CVSS v3 base score is 7.2 out of 10.