# CVE-2026-50411: Microsoft AD FS stack-based buffer overflow denial of service

Source: https://junglewise.ai/threats/cve-2026-50411-microsoft-ad-fs-stack-based-buffer-overflow-denial-of-service  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-14. Updated: 2026-07-14  
License: CC BY 4.0 with a link back

CVE-2026-50411 · Severity: high · CVSS 7.5 · Published 2026-07-14

A vulnerability exists in Microsoft's Active Directory Federation Services (AD FS), a component used to provide single sign-on access to systems and applications. An unauthorized attacker can exploit this flaw over the network to crash the service, preventing legitimate users from logging into their accounts or accessing corporate resources. This results in a significant disruption to business operations and identity management services.

Technologies: [Microsoft Active Directory Federation Services](https://junglewise.ai/threats/technologies/active-directory-federation-services), [Microsoft Windows 11](https://junglewise.ai/threats/technologies/windows-11), [Microsoft Windows 10](https://junglewise.ai/threats/technologies/windows-10), [Microsoft Windows Server 2012](https://junglewise.ai/threats/technologies/windows-server-2012). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-50411 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-50411 being exploited in the wild.

**How severe is CVE-2026-50411?** High severity, with a CVSS score of 7.5, published 14 July 2026.

**Which products and versions are affected?** Microsoft Active Directory Federation Services Included in affected Windows versions; Microsoft Windows 11 24H2, 25H2, 26H1; Microsoft Windows 10 1607, 1809, 21H2, 22H2; Microsoft Windows Server 2012 All versions.

**Is there a fix for CVE-2026-50411?** 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-2026-50411 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-50411?** Check whether you run Microsoft Active Directory Federation Services, Microsoft Windows 11, Microsoft Windows 10 or one of the others listed at an affected version. 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 stack-based buffer overflow (CWE-121) exists in Active Directory Federation Services (AD FS). The vulnerability is triggered when the service improperly handles specially crafted network requests, leading to memory corruption on the stack. An unauthenticated attacker can exploit this over the network (AV:N) with low complexity (AC:L) to cause the service to crash, resulting in a complete loss of availability (A:H) for authentication services. The flaw affects multiple versions of Windows and Windows Server; users should apply the latest security updates from Microsoft to remediate the issue.

## Affected products

- Microsoft Windows 10 1607, 1809, 21H2, 22H2
- Microsoft Windows 11 24H2, 25H2, 26H1
- Microsoft Windows Server 2012 All versions
- Microsoft Active Directory Federation Services (AD FS) Included in affected Windows versions

## Timeline

- 2026-07-14: disclosed: Vulnerability published by Microsoft and NVD
- 2026-07-14: advisory: Microsoft Security Response Center (MSRC) released update guide details

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50411](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50411)

## Related threats

- [Microsoft Windows Recovery Environment UEFI/BIOS password bypass](https://junglewise.ai/threats/cve-2026-116638-the-windows-recovery-environment-winre-in-windows-10-and-11-may)
- [Windows DNS Server out-of-bounds read](https://junglewise.ai/threats/cve-2026-97844-out-of-bounds-read-in-dns-server-allows-an-authorized-attacker-to)
- [Windows DNS Server out-of-bounds read information disclosure](https://junglewise.ai/threats/cve-2026-97843-out-of-bounds-read-in-dns-server-allows-an-authorized-attacker-to)
- [Windows DNS Server out-of-bounds read information disclosure](https://junglewise.ai/threats/cve-2026-97842-out-of-bounds-read-in-dns-server-allows-an-authorized-attacker-to)
- [Windows DNS Server out-of-bounds read](https://junglewise.ai/threats/cve-2026-97841-out-of-bounds-read-in-dns-server-allows-an-authorized-attacker-to)