CVE-2026-56020

HIGH 8.1

Webmin HTTP header authentication bypass

CVSS Score

8.1

EPSS Score

0.0%

EPSS Percentile

0th

The Webmin HTTP server (miniserv.pl) allows unauthenticated attackers to impersonate any user with a configured SSL client certificate by sending a forged HTTP header. A remote attacker can spoof certificate DNs and authenticate as any user. Fixed in 2.641.

CWE	CWE-290
Vendor	webmin
Product	webmin
Published	Jun 18, 2026

Stay Ahead of the Next One

Get instant alerts for webmin webmin

Be the first to know when new high vulnerabilities affecting webmin webmin are published — delivered to Slack, Telegram or Discord.

Get Free Alerts → Free · No credit card · 60 sec setup

CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

Webmin / Webmin

0 < 2.641

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/webmin/webmin/releases/tag/2.641 webmin.com: https://webmin.com/security/#webmin-prior-to-2641 raw.githubusercontent.com: https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-169-02.json cve.org: https://www.cve.org/CVERecord?id=CVE-2026-56020

Credits

Adem El Adeb, vulone.com/vul1.com