CVE-2026-3871

Name: CVE-2026-3871
Creator: NVD / NIST
Published: 2026-06-02T03:16:17.023+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.17%

Last modified Jun 17, 2026

CVE-2026-3871 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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.. EPSS estimates a 0.17% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.17%

6.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-120

References

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

Timeline

Published: Jun 2, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-3871?

How severe is CVE-2026-3871?

CVE-2026-3871 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.

How do I fix CVE-2026-3871?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-3871?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST