What’s Vulnerable › Vulnerabilities

CVE-2019-1126

• Severity: medium (CVSS 5.3 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 4.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2019-07-29 · updated 2026-06-17
• Weakness: CWE-307

Description

A security feature bypass vulnerability exists in Active Directory Federation Services (ADFS) which could allow an attacker to bypass the extranet lockout policy.To exploit this vulnerability, an attacker could run a specially crafted application, which would allow an attacker to launch a password brute-force attack or cause account lockouts in Active Directory.This security update corrects how ADFS handles external authentication requests., aka 'ADFS Security Feature Bypass Vulnerability'. This CVE ID is unique from CVE-2019-0975.

Affected products

• Microsoft Windows Server 2012: r2
• Microsoft Windows Server 2016: 1803, 1903
• Microsoft Windows Server 2019: all versions
• Microsoft Windows Server: 2012 R2, 2012 R2 (Core installation), 2016, 2016 (Core installation), version 1803 (Core Installation), 2019 (+1)
• Microsoft Windows Server, version 1903 (Server Core installation): all versions

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1126
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1126

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