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HIGH

CVE-2021-40186

CVSS v3

7.5

HIGH

EPSS Score

1.1 %

exploit probability, as of 2026-09-25

CISA KEV

No

known exploited

Exploitation

—

SSVC status

Description

The AppCheck research team identified a Server-Side Request Forgery (SSRF) vulnerability within the DNN CMS platform, formerly known as DotNetNuke. SSRF vulnerabilities allow the attacker to exploit the target system to make network requests on their behalf, allowing a range of possible attacks. In the most common scenario, the attacker exploits SSRF vulnerabilities to attack systems behind the firewall and access sensitive information from Cloud Provider metadata services.

Technical details

Published
2022-06-02

Frequently asked questions

What is CVE-2021-40186?

The AppCheck research team identified a Server-Side Request Forgery (SSRF) vulnerability within the DNN CMS platform, formerly known as DotNetNuke. SSRF vulnerabilities allow the attacker to exploit the target system to make network requests on their behalf, allowing a range of possible attacks. In the most common scenario, the attacker exploits SSRF vulnerabilities to attack systems behind the firewall and access sensitive information from Cloud Provider metadata services.

Is CVE-2021-40186 actively exploited?

Active exploitation of CVE-2021-40186 has not been confirmed. Its EPSS score was 1.1% on 2026-09-25, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-40186?

CVE-2021-40186 has a CVSS v3 base score of 7.5 (HIGH severity).

Is CVE-2021-40186 affecting your environment?

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