CVE-2026-56020

Webmin HTTP header authentication bypass

State: Published
Severity: 9.2 Critical
Published: Jun 18, 2026
Updated: Aug 11, 2026
Reserved: Jun 18, 2026

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 2.202.

Scores

CVSS	Score	Vector	Source
4.0	9.2 Critical	CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N	cisa-cg
3.1	8.1 High	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H	cisa-cg

Weaknesses

CWE-290 Authentication Bypass by Spoofing

Affected Products

Product	Versions
WebminWebmin	before 2.202Affected 2.202Not affected

References

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