CVE-2026-3871

Name of the Vulnerable Software and Affected Versions Zyxel VMG4005-B50B versions prior to 5.13(ABRL.5.4)C0

Description A buffer overflow occurs in the UPnP DeletePortMapping() command. This allows an adjacent attacker to cause a temporary denial-of-service (DoS) condition, which is a state where a system or network becomes unavailable to its intended users, specifically affecting the UPnP function of the device.

Recommendations Update to a version newer than 5.13(ABRL.5.4)C0. As a temporary workaround, consider restricting access to the DeletePortMapping() command to minimize the risk of exploitation.