CVE-2026-71942

Multiple DrayTek VigorSwitch models contain a buffer overflow vulnerability in the mail_mailalert function. The vulnerability is caused by concatenating multiple smtpReceiver email addresses into a fixed-size buffer without checking the remaining buffer size. 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.

Credits

Jincheng Wang (@winmt)
Le Yu (Nanjing University of Posts and Telecommunications)
Xiapu Luo (The Hong Kong Polytechnic University)

References