CVE-2026-71938 [HIGH] – Multiple DrayTek VigorSwitch models contain a buffer overflow vulnerability in the switch_

Multiple DrayTek VigorSwitch models contain a buffer overflow vulnerability in the switch_lan_gvrp function. The vulnerability is caused by unsafe copying of the portList field into an undersized buffer. A remote attacker can trigger this vulnerability via crafted input, causing a denial of service or potentially executing arbitrary commands. Exploitation requires valid administrative credentials for the device’s web management interface.