CVE-2026-3040: DrayTek Vigor 300B Web Management uploadlangs cgiGetFile os command injection
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 Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-3040?
CVE-2026-3040 is classified as a critical vulnerability due to the potential for remote code execution through OS command injection.
How do I fix CVE-2026-3040?
To mitigate CVE-2026-3040, update the DrayTek Vigor 300B firmware to version 1.5.1.7 or later.
What systems are affected by CVE-2026-3040?
CVE-2026-3040 affects DrayTek Vigor 300B devices running versions up to and including 1.5.1.6.
What kind of attack can exploit CVE-2026-3040?
CVE-2026-3040 can be exploited through remote attacks that utilize OS command injection via the web management interface.
Is CVE-2026-3040 being actively exploited?
There have been reports suggesting that CVE-2026-3040 may be actively exploited in the wild, emphasizing the need for immediate action.