CVE-2026-3871

MEDIUM

Zyxel VMG4005-B50B Firmware - Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

Title source: rule

Description

A buffer overflow vulnerability in the UPnP DeletePortMapping() command in Zyxel VMG4005-B50B firmware versions through 5.13(ABRL.5.4)C0 could allow an adjacent attacker to trigger a temporary denial-of-service (DoS) condition affecting the UPnP function of the affected device.

References (1)

Core 1

Core References

Vendor Advisory vendor-advisory

https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-buffer-overflow-vulnerabilities-in-the-upnp-function-of-certain-4g-lte-5g-nr-cpe-and-dsl-ethernet-cpe-06-02-2026

Scores

CVSS v3 6.5

EPSS 0.0002

EPSS Percentile 3.6%

Attack Vector ADJACENT_NETWORK

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-120

Status published

Products (1)

Zyxel/VMG4005-B50B firmware <= 5.13(ABRL.5.4)C0

Published Jun 02, 2026

Tracked Since Jun 02, 2026