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Vulnerability record · CVE-2018-8340 · published 15 August 2018

CVE-2018-8340: Microsoft windows server 2012 vulnerability

Microsoft · Windows Server 2012

A security feature bypass vulnerability exists when Active Directory Federation Services (AD FS) improperly handles multi-factor authentication requests, aka "AD FS Security Feature Bypass Vulnerability." This affects Windows Server 2016, Windows Server 2012 R2, Windows 10 Servers.

6.5 CVSS 3.0 Medium EPSS 7.6% · top 5.7%
6.5CVSS 3.0 base score, v2 4.0
7.6%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
6References
17 Jun 2026Last modified by NVD

Description

A security feature bypass vulnerability exists when Active Directory Federation Services (AD FS) improperly handles multi-factor authentication requests, aka "AD FS Security Feature Bypass Vulnerability." This affects Windows Server 2016, Windows Server 2012 R2, Windows 10 Servers.

CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected products

2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://www.securityfocus.com/bid/105029 Third Party AdvisoryVDB Entry
http://www.securitytracker.com/id/1041474 Third Party AdvisoryVDB Entry
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8340 PatchVendor Advisory
http://www.securityfocus.com/bid/105029 Third Party AdvisoryVDB Entry
http://www.securitytracker.com/id/1041474 Third Party AdvisoryVDB Entry
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8340 PatchVendor Advisory

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2018-8340), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.