Users File Injection Vulnerability in Webmin by Cloudmin Technologies

CVE-2026-126781

What is CVE-2026-126781?

Webmin, up to version 2.670, has a critical flaw in the acl/cert_issue.cgi component, where authenticated users can exploit unvalidated certificate DN fields. By injecting newlines through a backslash and newline sequence, an attacker can add unauthorized root entries, which may allow them to obtain root access to Webmin after a restart of miniserv. This vulnerability emphasizes the importance of secure input validation in web applications, particularly in sensitive areas like user management and access control.

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