CVE-2026-50355 — Windows Active Directory Federation Services Denial of Service Vulnerability

Executive Summary

Stack-based buffer overflow in Active Directory Federation Services allows an unauthorized attacker to deny service over a network.

Overview

7.5

CVSS HIGH

Important

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Denial of Service

Released Jul 14 2026

Last Updated Jul 14 2026

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

CVSS Vector

ATTACK VECTOR

Network

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

None

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

None

INTEGRITY

None

AVAILABILITY

High

EXPLOIT CODE MATURITY

Unproven

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 6.5

EPSS Score

No EPSS score available for this CVE.

View on FIRST.org

Affected Products

15 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 10 Version 1607 for 32-bit Systems	`5099535 (Security Update)`	Important	Denial of Service	Yes
Windows 10 Version 1607 for x64-based Systems	`5099535 (Security Update)`	Important	Denial of Service	Yes
Windows 10 Version 1809 for 32-bit Systems	`5099538 (Security Update)`	Important	Denial of Service	Yes
Windows 10 Version 1809 for x64-based Systems	`5099538 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2012	`5099445 (Monthly Rollup)`	Important	Denial of Service	Yes
Windows Server 2012 (Server Core installation)	`5099445 (Monthly Rollup)`	Important	Denial of Service	Yes
Windows Server 2012 R2	`5099444 (Monthly Rollup)`	Important	Denial of Service	Yes
Windows Server 2012 R2 (Server Core installation)	`5099444 (Monthly Rollup)`	Important	Denial of Service	Yes
Windows Server 2016	`5099535 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2016 (Server Core installation)	`5099535 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2019	`5099538 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2019 (Server Core installation)	`5099538 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2022	`5099540 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2025	`5099536 (Security Update)`	Important	Denial of Service	Yes
Windows Server 2025 (Server Core installation)	`5099536 (Security Update)`	Important	Denial of Service	Yes

Patches

6 patches

Article	Type	Restart
`5099535`	Security Update	Yes
`5099538`	Security Update	Yes
`5099445`	Monthly Rollup	Yes
`5099444`	Monthly Rollup	Yes
`5099540`	Security Update	Yes
`5099536`	Security Update	Yes

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

Anonymous

References

MSRC Advisory MITRE NVD