CVE-2026-126781

EUVD-2026-123775
Webmin through 2.670 contains a users file injection vulnerability in acl/cert_issue.cgi that allows authenticated Webmin users to inject lines by supplying unvalidated certificate DN fields containing newlines. Attackers can end a DN field with a backslash and newline to add a second root entry with a known password hash, gaining Webmin root access after miniserv restarts.
CRLF Injection
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
VulnCheckCNA
7.5 HIGH
NETWORK
HIGH
LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources (CNA/ADP records, vendor advisories, Enginsight analysis).
VendorProductVersionSource
webminwebmin
𝑥
≤ 2.670
CNA
Common Weakness Enumeration
References
https://github.com/webmin/webmin/blob/2.670/acl/cert_issue.cgi#L22-L52
https://github.com/webmin/webmin/commit/0c449e341746d8c445c8c7db223eac1f41755943
https://github.com/webmin/webmin/commit/8fb194e5fbc30a6664545d48940d03759ace9bf2
https://www.vulncheck.com/advisories/webmin-through-2.670-users-file-injection-via-acl-cert-issue-cgi