# CVE-2026-70005: Microsoft Active Directory Federation Services weak authentication bypass

Source: https://junglewise.ai/threats/cve-2026-70005-weak-authentication-in-active-directory-federation-services-ad-fs  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-28  
License: CC BY 4.0 with a link back

CVE-2026-70005 · Severity: medium · CVSS 5.9 · Published 2026-10-13

Active Directory Federation Services (AD FS) is the identity provider Microsoft uses to manage authentication and authorization for enterprise applications. A weak authentication implementation allows attackers on the network to bypass security features and potentially gain unauthorized access to federated applications and resources.

Technologies: [Microsoft Windows Server 2019](https://junglewise.ai/threats/technologies/windows-server-2019), [Microsoft Windows Server 2022](https://junglewise.ai/threats/technologies/windows-server-2022), [Microsoft Windows Server 2025](https://junglewise.ai/threats/technologies/windows-server-2025). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-70005 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-70005 being exploited in the wild.

**How severe is CVE-2026-70005?** Medium severity, with a CVSS score of 5.9, published 13 October 2026.

**Which products and versions are affected?** Active Directory Federation Services.

**Is there a fix for CVE-2026-70005?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-70005 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-70005?** Check whether you run Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Windows Server 2025 or one of the others listed. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A weak authentication vulnerability in AD FS permits network-based attackers to bypass security controls without prior authentication. The vulnerability stems from insufficient validation of authentication requests, allowing an attacker to circumvent intended access restrictions. The flaw is remotely exploitable and has been addressed by Microsoft.

## Affected products

- Active Directory Federation Services

## Timeline

- 2026-10-13: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70005](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70005)

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