CVE-2026-58391 OPNsense: Stored XSS in Firewall Rules/NAT pages via a HTML-attribute breakout

OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.11, Firewall Rules and NAT views place stored category names and alias descriptions into HTML title attributes in filterrule.volt and natrule.volt without quote-safe encoding. The response layer uses ENTNOQUOTES, so ...