CVE-2026-3040: DrayTek VIGOR300B Firmware

High severity, CVSS 7.2. EPSS: 7.2% chance of exploitation in the next 30 days.

A vulnerability was identified in DrayTek Vigor 300B up to 1.5.1.6. This affects the function cgiGetFile of the file /cgi-bin/mainfunction.cgi/uploadlangs of the component Web Management Interface. The manipulation of the argument File leads to os command injection. The attack may be initiated remotely. The exploit is publicly available and might be used. The vendor confirms that "300B is EoL, and this is an authenticated vulnerability. We don't plan to fix it." This vulnerability only affects products that are no longer supported by the maintainer.

Affected products

• DrayTek VIGOR300B Firmware: up to and including 1.5.1.6

Published 2026-02-23. Last modified 2026-06-17.