# CVE-2019-1126: ADFS Security Feature Bypass Vulnerability

CVE-2019-1126 is fixed in 8 products on 1 platform, first by KB4507460, released July 9, 2019. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2019-1126
- Priority: Routine
- CVSS: 5.3 (Important)
- EPSS: 0.0495
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation Less Likely
- Published: Jul 9, 2019
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2019-1126

## Description

<p>A security feature bypass vulnerability exists in Active Directory Federation Services (ADFS) which could allow an attacker to bypass the extranet lockout policy.</p> <p>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.</p> <p>This security update corrects how ADFS handles external authentication requests.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Windows Server 2012 R2 |  | [KB4507457](https://patchblox.com/security/data/fix/microsoft/kb4507457.md) | Jul 9, 2019 |
| Microsoft | Windows Server 2012 R2 |  | [KB4507448](https://patchblox.com/security/data/fix/microsoft/kb4507448.md) | Jul 9, 2019 |
| Microsoft | Windows Server 2012 R2 (Server Core installation) |  | [KB4507457](https://patchblox.com/security/data/fix/microsoft/kb4507457.md) | Jul 9, 2019 |
| Microsoft | Windows Server 2012 R2 (Server Core installation) |  | [KB4507448](https://patchblox.com/security/data/fix/microsoft/kb4507448.md) | Jul 9, 2019 |
| Microsoft | Windows Server 2016 | 14393.3085 | [KB4507460](https://patchblox.com/security/data/fix/microsoft/kb4507460.md) | Jul 9, 2019 |
| Microsoft | Windows Server 2016 (Server Core installation) | 14393.3085 | [KB4507460](https://patchblox.com/security/data/fix/microsoft/kb4507460.md) | Jul 9, 2019 |
| Microsoft | Windows Server 2019 | 17763.615 | [KB4507469](https://patchblox.com/security/data/fix/microsoft/kb4507469.md) | Jul 9, 2019 |
| Microsoft | Windows Server 2019 (Server Core installation) | 17763.615 | [KB4507469](https://patchblox.com/security/data/fix/microsoft/kb4507469.md) | Jul 9, 2019 |
| Microsoft | Windows Server, version 1803  (Server Core Installation) | 17134.885 | [KB4507435](https://patchblox.com/security/data/fix/microsoft/kb4507435.md) | Jul 9, 2019 |
| Microsoft | Windows Server, version 1903 (Server Core installation) | 18362.239 | [KB4507453](https://patchblox.com/security/data/fix/microsoft/kb4507453.md) | Jul 9, 2019 |

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Data as of 2026-11-07T18:46:35Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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