How severe is CVE-2026-36539?

CVE-2026-36539 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-2026-36539 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-36539?

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-2026-36539 have an EU (EUVD) identifier?

Yes. CVE-2026-36539 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32686.

When was CVE-2026-36539 published?

CVE-2026-36539 was published on 2026-05-27 and last updated on 2026-06-17.

CVE-2026-36539

CVE-2026-36539 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% (28th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-32686
Weakness: CWE-200
Published: 2026-05-27
Last modified: 2026-06-17

Description

Netis AC1200 Router NC21 V4.0.1.4296 exposes a CGI endpoint /cgi-bin/skk_get.cgi that returns the entire router configuration as a JSON response with no authentication required. Any attacker on the LAN can send a single HTTP GET request and instantly retrieve administrator credentials, WiFi passwords, PPPoE credentials, DDNS credentials, and a full map of all connected devices.

Frequently asked questions

What is CVE-2026-36539?: Netis AC1200 Router NC21 V4.0.1.4296 exposes a CGI endpoint /cgi-bin/skk_get.cgi that returns the entire router configuration as a JSON response with no authentication required. Any attacker on the LAN can send a single HTTP GET request and instantly retrieve administrator credentials, WiFi passwords, PPPoE credentials, DDNS credentials, and a full map of all connected devices.
How severe is CVE-2026-36539?: CVE-2026-36539 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-2026-36539 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-36539?: 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-2026-36539 have an EU (EUVD) identifier?: Yes. CVE-2026-36539 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32686.
When was CVE-2026-36539 published?: CVE-2026-36539 was published on 2026-05-27 and last updated on 2026-06-17.

References

https://github.com/sir3ns/cve-disclosure/blob/main/CVE-2026-36539/readme.md

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