What is CVE-2026-58394?

CVE-2026-58394 is a medium-severity vulnerability in Opnsense Core, classified under Cross-site Scripting. CVSS score: 5.2/10. Published 2026-10-15.

How severe is CVE-2026-58394?

Medium severity. CVSS v3 base score is 5.2 out of 10.

XSS in Opnsense Core

CVE-2026-58394

OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.11, src/www/system_advanced_admin.php reads certificate records into $a_cert but omits that array from legacy_html_escape_form_data() before rendering each certificate descr value in the SSL Certificate selector. The certificate description accepts HTML metacharacters, allowing a user with the page-system-certmanager privilege to store markup that executes when another user opens System Settings Administration. This issue is fixed in version 26.1.11.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2026-10-15 · last modified 2026-10-15.

CVSS v3 metric

CVSS v3 base score 5.2 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Opnsense Core — versions < 26.1.11

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

Frequently asked questions

What is CVE-2026-58394?: CVE-2026-58394 is a medium-severity vulnerability in Opnsense Core, classified under Cross-site Scripting. CVSS score: 5.2/10. Published 2026-10-15.
How severe is CVE-2026-58394?: Medium severity. CVSS v3 base score is 5.2 out of 10.