How severe is CVE-2026-36611?

CVE-2026-36611 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-36611 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-36611?

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-2026-36611 have an EU (EUVD) identifier?

Yes. CVE-2026-36611 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34150.

When was CVE-2026-36611 published?

CVE-2026-36611 was published on 2026-06-03 and last updated on 2026-06-17.

CVE-2026-36611

CVE-2026-36611 is a high-severity vulnerability with a CVSS 3.x base score of 7.3. 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-200.

Key facts

Severity: High (CVSS 3.x base score 7.3)
EPSS exploit prediction: 0% (14th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-34150
Weakness: CWE-200
Published: 2026-06-03
Last modified: 2026-06-17

Description

Mercusys AC12G (EU) V1 with firmware AC12G(EU)_V1_200909 returns 128 bytes of uninitialized buffer when receiving POST requests without SOAPAction header on UPnP port 1900, exposing internal memory to unauthenticated adjacent network attackers.

Frequently asked questions

What is CVE-2026-36611?: Mercusys AC12G (EU) V1 with firmware AC12G(EU)_V1_200909 returns 128 bytes of uninitialized buffer when receiving POST requests without SOAPAction header on UPnP port 1900, exposing internal memory to unauthenticated adjacent network attackers.
How severe is CVE-2026-36611?: CVE-2026-36611 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-36611 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-36611?: 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-2026-36611 have an EU (EUVD) identifier?: Yes. CVE-2026-36611 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-34150.
When was CVE-2026-36611 published?: CVE-2026-36611 was published on 2026-06-03 and last updated on 2026-06-17.

References

https://github.com/Tymbark7372/MERCUSYS-AC12G/blob/master/advisories/CVE-2026-36611.md

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