XSS in Opnsense

CVE-2019-25377

OPNsense 19.1 contains a reflected cross-site scripting vulnerability in the system_advanced_sysctl.php endpoint that allows attackers to inject malicious scripts via the value parameter. Attackers can craft POST requests with script payloads in the value parameter to execute JavaScript in the context of authenticated user sessions.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (15.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2019-25377?
CVE-2019-25377 is a medium-severity vulnerability in Opnsense, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-02-15.
How severe is CVE-2019-25377?
Medium severity. CVSS v3 base score is 5.4 out of 10.