How severe is CVE-2021-40186?

CVE-2021-40186 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-40186 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-40186?

CVE-2021-40186 affects Dnnsoftware Dotnetnuke. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-40186?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-40186 published?

CVE-2021-40186 was published on 2022-06-02 and last updated on 2026-06-17.

CVE-2021-40186

CVE-2021-40186 is a medium-severity vulnerability in Dnnsoftware Dotnetnuke with a CVSS 3.x base score of 6.5. 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-918.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (60th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-918
Affected product: Dnnsoftware Dotnetnuke
Published: 2022-06-02
Last modified: 2026-06-17

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.

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.
How severe is CVE-2021-40186?: CVE-2021-40186 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-40186 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-40186?: CVE-2021-40186 affects Dnnsoftware Dotnetnuke. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-40186?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-40186 published?: CVE-2021-40186 was published on 2022-06-02 and last updated on 2026-06-17.

References

https://appcheck-ng.com/dnn-cms-server-side-request-forgery-cve-2021-40186

Affected products (1)

cpe:2.3:a:dnnsoftware:dotnetnuke:*:*:*:*:*:*:*:*

More vulnerabilities in Dnnsoftware Dotnetnuke

CVE-2025-64095 — Critical (CVSS 10.0): DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to…
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