CVE-2026-56020

HIGH

Webmin HTTP header authentication bypass

Title source: cna
STIX 2.1

Description

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.

Scores

CVSS v3 8.1
EPSS 0.0050
EPSS Percentile 39.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-290
Status published
Products (2)
Webmin/Webmin < 2.641
Webmin/Webmin 2.641
Published Jun 18, 2026
Tracked Since Jun 18, 2026