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TI-2026-72131 Aliases CVE-2026-70005GHSA-5p73-5qgx-x842

Weak authentication in AD FS lets attackers bypass a security feature

Priority LOW 27CWE-1390Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
None · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

Microsoft Windows Server 2019, Windows Server 2022 and Windows Server 2025 are affected by a flaw in Active Directory Federation Services (AD FS), in versions from 10.0.17763.0 before 10.0.17763.9376, from 10.0.20348.0 before 10.0.20348.5761 and from 10.0.26100.0 before 10.0.26100.33650. Weak authentication (CWE-1390) lets an unauthorized attacker bypass a security feature over a network. The attack needs no privileges and no user interaction.

Written with Claude Haiku 5.5 from the sources below · 2026-10-27

Description from the CNA

Weak authentication in Active Directory Federation Services (AD FS) allows an unauthorized attacker to bypass a security feature over a network.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00628 50th percentileScored 2026-11-07
Fix Fixed Windows Server 2019 (Microsoft): 10.0.17763.9376Windows Server 2019 (Server Core installation) (Microsoft): 10.0.17763.9376+3 more products

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MicrosoftWindows Server 201910.0.17763.0 to before 10.0.17763.937610.0.17763.9376Patch availableCNA
MicrosoftWindows Server 2019 (Server Core installation)10.0.17763.0 to before 10.0.17763.937610.0.17763.9376Patch availableCNA
MicrosoftWindows Server 202210.0.20348.0 to before 10.0.20348.576110.0.20348.5761Patch availableCNA
MicrosoftWindows Server 202510.0.26100.0 to before 10.0.26100.3365010.0.26100.33650Patch availableCNA
MicrosoftWindows Server 2025 (Server Core installation)10.0.26100.0 to before 10.0.26100.3365010.0.26100.33650Patch availableCNA
  • Windows Server 2019 VendorMicrosoft Affected 10.0.17763.0 to before 10.0.17763.9376 Fixed in 10.0.17763.9376 Patch available CNA
  • Windows Server 2019 (Server Core installation) VendorMicrosoft Affected 10.0.17763.0 to before 10.0.17763.9376 Fixed in 10.0.17763.9376 Patch available CNA
  • Windows Server 2022 VendorMicrosoft Affected 10.0.20348.0 to before 10.0.20348.5761 Fixed in 10.0.20348.5761 Patch available CNA
  • Windows Server 2025 VendorMicrosoft Affected 10.0.26100.0 to before 10.0.26100.33650 Fixed in 10.0.26100.33650 Patch available CNA
  • Windows Server 2025 (Server Core installation) VendorMicrosoft Affected 10.0.26100.0 to before 10.0.26100.33650 Fixed in 10.0.26100.33650 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:x64:*before 10.0.17763.9376VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:x64:*before 10.0.20348.5761VulnerableMicrosoft
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*before 10.0.26100.33650VulnerableMicrosoft
  • cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:x64:* Versions before 10.0.17763.9376 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:x64:* Versions before 10.0.20348.5761 Vulnerable ·Microsoft
  • cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:* Versions before 10.0.26100.33650 Vulnerable ·Microsoft

Remediation

Windows Server 2019 and Windows Server 2019 (Server Core installation) are fixed in 10.0.17763.9376. Windows Server 2022 is fixed in 10.0.20348.5761. Windows Server 2025 and Windows Server 2025 (Server Core installation) are fixed in 10.0.26100.33650.

Written with Claude Haiku 5.5 from the sources below · 2026-10-27

  • Fix · CNA Windows Server 2019 (Microsoft) Fixed in 10.0.17763.9376
  • Fix · CNA Windows Server 2019 (Server Core installation) (Microsoft) Fixed in 10.0.17763.9376
  • Fix · CNA Windows Server 2022 (Microsoft) Fixed in 10.0.20348.5761
  • Fix · CNA Windows Server 2025 (Microsoft) Fixed in 10.0.26100.33650
  • Fix · CNA Windows Server 2025 (Server Core installation) (Microsoft) Fixed in 10.0.26100.33650

Timeline

  1. 2026-10-13 Threatist record created from CVE-2026-70005
  2. 2026-10-13 Alias added: GHSA-5p73-5qgx-x842
  3. 2026-10-14 Priority changed: MEDIUM → LOW
  4. 2026-10-15 CISA SSVC decision points changed
  5. 2026-10-25 EPSS moved to the 50th–90th percentile

References

Patch 1

  • TI-2026-26194 Windows Internet Key Exchange (IKE) Service Extensions Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
  • TI-2025-36863 Windows Server Update Service (WSUS) Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
  • TI-2020-01431 Netlogon Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 10.0
  • TI-2020-01310 Improper input validation in Microsoft Windows Server KEVCVSS 3.1CRITICAL 10.0
  • TI-2026-73128 Windows Shell Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
  • TI-2026-17367 MSHTML Framework Security Feature Bypass Vulnerability KEVCVSS 3.1HIGH 8.8
See all 6455 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences