CVE-2026-58390EPSS p39.7%

CVE-2026-58390CVE-2026-58390

Description

OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.11, the OpenVPN connection-status dashboard widget in src/opnsense/www/js/widgets/OpenVPNClients.js and the connection-status view place a client common_name into data-common-name attributes without quote-safe encoding. Exploitation requires an OpenVPN server configured with username-as-common-name and RADIUS or LDAP authentication, plus the ability to provision or self-register a valid backend username containing a double quote; deployments where the same administrator controls both the identity backend and firewall do not cross a separate trust boundary. An authenticated client using that username can close the attribute and add an event handler, while the local user database is not affected because its username validator rejects quotes. Script executes in an administrator's session when the administrator opens the dashboard or connection-status page and the injected event is triggered; the demonstrated

Scoring

CVSS 8.0 ()
VectorCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H
EPSS0.48% probability of exploitation · percentile 39.7% · 2026-10-17T12:00:28Z
Last modified2026-10-15
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.