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.

• https://github.com/opnsense/core/commit/9d0a590e9c49f4374a5539929b366123f63bc9eb
• https://github.com/opnsense/core/commit/adcb02f8f68071e636bf9660b2cb8d0229f34674
• https://github.com/opnsense/core/security/advisories/GHSA-8pgr-x852-qx4j
• https://hackerask.com/posts/opnsense
• https://github.com/opnsense/core/security/advisories/GHSA-8pgr-x852-qx4j