OPNsense up to 26.1.10 Dashboard Widget OpenVPNClients.js common_name cross site scripting

Summaryinfo

A vulnerability was found in OPNsense up to 26.1.10. It has been declared as problematic. This affects an unknown function of the file src/opnsense/www/js/widgets/OpenVPNClients.js of the component Dashboard Widget. Such manipulation of the argument common_name leads to cross site scripting. This vulnerability is uniquely identified as CVE-2026-58390. The attack can be launched remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in OPNsense up to 26.1.10 and classified as problematic. Affected by this issue is some unknown processing of the file src/opnsense/www/js/widgets/OpenVPNClients.js of the component Dashboard Widget. The manipulation of the argument common_name with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Impacted is integrity. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-58390 since 06/30/2026. The exploitation is known to be easy. The attack may be launched remotely. Additional levels of successful authentication are required for exploitation. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 26.1.11 eliminates this vulnerability.

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Productinfo

Name

• OPNsense

Version

• 26.1.0
• 26.1.1
• 26.1.2
• 26.1.3
• 26.1.4
• 26.1.5
• 26.1.6
• 26.1.7
• 26.1.8
• 26.1.9
• 26.1.10

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