What is CVE-2026-36603?

CVE-2026-36603 is a high-severity vulnerability in N/a, classified under Missing Authentication for Critical Function. CVSS score: 8.1/10. Published 2026-06-03.

How severe is CVE-2026-36603?

High severity. CVSS v3 base score is 8.1 out of 10.

Auth bypass in N/a

CVE-2026-36603

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)_V1_200909 exposes 15 of 18 UPnP IGD actions without authentication on port 1900, including AddPortMapping and GetExternalIPAddress. UPnP is enabled by default through the admin interfac…

Vulnerability class: Broken Authentication

EPSS: 0.000 (6.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

N/a — versions n/a

Weakness classification (CWE)

CWE-306 — Missing Authentication for Critical Function

References

cve@mitre.org

Frequently asked questions

What is CVE-2026-36603?: CVE-2026-36603 is a high-severity vulnerability in N/a, classified under Missing Authentication for Critical Function. CVSS score: 8.1/10. Published 2026-06-03.
How severe is CVE-2026-36603?: High severity. CVSS v3 base score is 8.1 out of 10.