CVE-2020-8821
MediumAn Improper Data Validation Vulnerability exists in Webmin 1.941 and earlier affecting the Command Shell Endpoint.
Published Oct 12, 2020 · Updated Aug 7, 2026
Key Facts
Patch immediately- CVE-2020-8821 is a medium-severity vulnerability (CVSS 5.4 v3.1) affecting Webmin.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 79% probability of exploitation in the next 30 days.
- Fixed versions are available, including Webmin <=1.941, Webmin 1.941.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v3.1
5.4
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS (30-day exploit likelihood)
79%
Higher than 99.5% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
None known
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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.
Affected Products
1 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| WebminWebmin | See advisory | 1.941 |
Patched Releases
Webmin
<=1.941
Timeline
Publicly disclosed
Oct 12, 2020
Last updated
Aug 7, 2026
Weakness Type
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
References
FAQ
Common Questions.
An Improper Data Validation Vulnerability exists in Webmin 1.941 and earlier affecting the Command Shell Endpoint.
Affected: Webmin. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including Webmin <=1.941, Webmin 1.941.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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