How severe is CVE-2020-8821?

CVE-2020-8821 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2020-8821 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 82% (100th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-8821?

CVE-2020-8821 affects Webmin. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-8821?

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

When was CVE-2020-8821 published?

CVE-2020-8821 was published on 2020-10-12 and last updated on 2026-06-17.

CVE-2020-8821

CVE-2020-8821 is a medium-severity vulnerability in Webmin with a CVSS 3.x base score of 5.4. Its EPSS exploit-prediction score of 82% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 3.5
EPSS exploit prediction: 82% (100th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Webmin
Published: 2020-10-12
Last modified: 2026-06-17

Description

An Improper Data Validation Vulnerability exists in Webmin 1.941 and earlier affecting the Command Shell Endpoint. A user may enter HTML code into the Command field and submit it. Then, after visiting the Action Logs Menu and displaying logs, the HTML code will be rendered (however, JavaScript is not executed). Changes are kept across users.

Frequently asked questions

What is CVE-2020-8821?: An Improper Data Validation Vulnerability exists in Webmin 1.941 and earlier affecting the Command Shell Endpoint. A user may enter HTML code into the Command field and submit it. Then, after visiting the Action Logs Menu and displaying logs, the HTML code will be rendered (however, JavaScript is not executed). Changes are kept across users.
How severe is CVE-2020-8821?: CVE-2020-8821 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2020-8821 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 82% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-8821?: CVE-2020-8821 affects Webmin. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-8821?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-8821 published?: CVE-2020-8821 was published on 2020-10-12 and last updated on 2026-06-17.

References

https://www.webmin.com/security.html

Affected products (1)

cpe:2.3:a:webmin:webmin:*:*:*:*:*:*:*:*

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