CVE-2026-58390
8.0HighPublished 15 Oct 2026 · NVD status: Deferred · AI triage by gemini-3.8-flash
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- Required
- Impact
- Full C/I/A compromise
- Weakness
- CWE-79
Impact
Authenticated VPN users can achieve root command execution and read config.xml via stored XSS in an administrator's browser session. Attackers need a RADIUS or LDAP account with a double quote in the username connecting to an OpenVPN instance using username-as-common-name, plus an admin viewing the connection dashboard.
Root cause
The OpenVPN client status widget inserts the client common_name into an HTML data-common-name attribute without escaping double quotes.
Affected systems
OPNsense prior to version 26.1.11
CVSS v3.1 · CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H
Fix & remediation
Upgrade OPNsense to version 26.1.11 or later. If patching immediately is not possible, disable the username-as-common-name setting on OpenVPN servers or restrict/sanitize double quotes in LDAP/RADIUS usernames.
$ opnsense-update && opnsense-shell rebootAI-suggested. Run it in staging first and check it against the vendor advisory. Why?
NVD 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 payload used pointer movement over the client row rather than unconditional page-load execution. The advisory demonstrates that the script can read config.xml, invoke privileged APIs, reset the root password, and obtain root command execution. This issue is fixed in version 26.1.11.