How severe is CVE-2026-36608?

CVE-2026-36608 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-36608 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-36608?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-36608 have an EU (EUVD) identifier?

Yes. CVE-2026-36608 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34147.

When was CVE-2026-36608 published?

CVE-2026-36608 was published on 2026-06-03 and last updated on 2026-06-17.

CVE-2026-36608

CVE-2026-36608 is a high-severity vulnerability with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-441.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 0% (8th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-34147
Weakness: CWE-441
Published: 2026-06-03
Last modified: 2026-06-17

Description

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)_V1_200909 allows UPnP AddPortMapping to forward external ports to the router's own admin interface by accepting its own IP (192.168.1.1) or localhost (127.0.0.1) as InternalClient. An unauthenticated LAN attacker can expose the admin panel to the internet with a single SOAP request.

Frequently asked questions

What is CVE-2026-36608?: Mercusys AC12G (EU) V1 router with firmware AC12G(EU)_V1_200909 allows UPnP AddPortMapping to forward external ports to the router's own admin interface by accepting its own IP (192.168.1.1) or localhost (127.0.0.1) as InternalClient. An unauthenticated LAN attacker can expose the admin panel to the internet with a single SOAP request.
How severe is CVE-2026-36608?: CVE-2026-36608 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-36608 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-36608?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-36608 have an EU (EUVD) identifier?: Yes. CVE-2026-36608 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34147.
When was CVE-2026-36608 published?: CVE-2026-36608 was published on 2026-06-03 and last updated on 2026-06-17.

References

https://github.com/Tymbark7372/MERCUSYS-AC12G/blob/master/advisories/CVE-2026-36608.md

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