Vulnerability Report

CVE-2026-56022

Title: MFA bypass via User-Agent header

Other

Proof Of Concept

No public PoC currently indexed for CVE-2026-56022.

CWE Category CWE-308

Published Date Jun 18, 2026

Modified Date Aug 11, 2026

Exploit Status Not Found

Score 6.9 CVSS v4.0

Exploit Probability (EPSS)

0.55%

Vulnerability Summary

CVE-2026-56022: Webmin accepts basic authentication without session cookies when an attacker provides the 'User-Agent: webmin' header, allowing bypass of additional MFA requirements. Fixed in 2.640.

Impacted Vendors

gentoo 1

webmin 1

Reference Links

https://github.com/webmin/webmin/releases/tag/2.641 https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-169-02.json https://webmin.com/security/#webmin-prior-to-2641 https://www.cve.org/CVERecord?id=CVE-2026-56022

CVSS v4.0

Source Entity 9119a7d8-5eab-497f-8521-727c672e3725

Severity MEDIUM

6.9

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

N/A

RAW VECTOR

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1