RCE in Webmin Usermin
CVE-2026-123620
Usermin through 2.570 contains an OS command injection vulnerability in the Read Mail module that allows authenticated users to execute commands through unsanitized IMAP folder names. Attackers can create a folder containing shell metacharacters via an external IMAP client, then delete it in Usermin to run commands as their system account, bypassing webmail-only restrictions.
Vulnerability class: Command Injection (OS Command Injection)
Published .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/webmin/usermin (product)
- delete_folder in mailbox-lib.pl (technical-description)
- Fix commit 8a45420 (patch)
- GitHub Issue #142 (issue-tracking)
- Researcher write-up (technical-description)
- VulnCheck Advisory: Usermin through 2.570 OS Command Injection via Read Mail IMAP Folder Deletion (third-party-advisory)
Frequently asked questions
- What is CVE-2026-123620?
- CVE-2026-123620 is a high-severity vulnerability in Webmin Usermin, classified under OS Command Injection. CVSS score: 7.5/10. Published 2026-11-06.
- How severe is CVE-2026-123620?
- High severity. CVSS v3 base score is 7.5 out of 10.