by Kastro
Paper/Archive/CVE-2026-56020

CVE-2026-56020

Webmin Webmin — Webmin HTTP header authentication bypass

EPSS 0.5%CVSS 9.2
critical.is priorityof 100
36
CVSS 9.2 (CNA)9.2 / 10 × 3027.6Not in CISA KEV+300.0EPSS percentile 42.5.425 × 208.5No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
Webmin< 2.2022.202CNA

Scores by source

cisa-cg (CNA)9.2CVSS: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 (CNA)8.1CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

refgithub.com/webmin/webmin/releases/tag/2.202refwebmin.com/security/#webmin-prior-to-2202refraw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-169-02.jsonrefcve.org/CVERecord?id=CVE-2026-56020