High severity · published Jun 18, 2026
CVE-2026-56020
Webmin HTTP header authentication bypass
8.1
CVSS
0.5%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 42% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WE
Webmin · Webmin
before 2.202 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-56020
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-56020
github.com
https://github.com/webmin/webmin/releases/tag/2.202
raw.githubusercontent.com
https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-169-02.json
webmin.com
https://webmin.com/security/#webmin-prior-to-2202
www.cve.org
https://www.cve.org/CVERecord?id=CVE-2026-56020
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