EUVD-2026-43906
GHSA-jw44-x36j-888r
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Remote, unauthenticated, low-complexity network request crashes the service (AV:N/AC:L/PR:N/UI:N); impact is availability-only DoS, so C:N/I:N/A:H with unchanged scope.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Lifecycle Timeline
2DescriptionCVE.org
Stack-based buffer overflow in Active Directory Federation Services allows an unauthorized attacker to deny service over a network.
AnalysisAI
Denial of service in Microsoft Active Directory Federation Services (AD FS) allows a remote, unauthenticated attacker to crash or render the federation service unavailable by triggering a stack-based buffer overflow over the network. The flaw affects the AD FS role across Windows Server 2012 through 2025 (including Server Core installations) and carries a CVSS 7.5 rating driven entirely by availability impact. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires network reachability to a running AD FS server's federation endpoint; the CVSS vector (AV:N/AC:L/PR:N/UI:N) confirms no authentication, no user interaction, and low attack complexity, so against a reachable AD FS instance no special conditions apply beyond the AD FS role being installed and accepting network requests. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) describes a network-reachable, low-complexity, unauthenticated attack with no user interaction whose sole consequence is high availability impact - a pure denial of service with no confidentiality or integrity loss. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker with network access to the AD FS service - for example through an internet-exposed Web Application Proxy or from an internal foothold - sends a specially crafted request to the vulnerable AD FS endpoint that overflows a stack buffer during parsing, crashing the service. Because no authentication or user interaction is required (PR:N/UI:N) and complexity is low (AC:L), the attacker can repeatedly trigger the fault to keep federated SSO offline. … |
| Remediation | Patch available per vendor advisory: apply the Microsoft security update for CVE-2026-50355 detailed at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50355, selecting the KB package matching each AD FS server's Windows Server version (2012 through 2025, including Server Core). … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, identify all Windows Server instances running AD FS (versions 2012 through 2025, including Server Core) and verify their current patch level against Microsoft's security advisory. …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
More in Windows 10 Version 1607
View allLocal privilege escalation in Microsoft Active Directory Federation Services (AD FS) lets an already-authenticated low-p
Local privilege escalation in the Microsoft Windows Kernel allows an unauthorized attacker to gain elevated (SYSTEM-leve
Local privilege escalation in the Windows Win32K kernel subsystem (CWE-122 heap-based buffer overflow) lets an already-a
Local code execution in the Windows DHCP Client service stems from a use-after-free (CWE-416) memory-corruption flaw aff
Local code execution in the Microsoft Message Queuing (MSMQ) Queue Manager affects a broad range of Windows client and s
Remote code execution in the Microsoft Windows DHCP Server role allows an unauthenticated network attacker to run arbitr
Elevation of privilege in the Windows NTFS file-system driver lets an already-authenticated local user escalate to SYSTE
Local code execution in the Windows Media component of supported Windows 10, Windows 11, and Windows Server (2016 throug
Elevation of privilege in the Windows Hyper-V virtual network switch (VMSwitch) lets an authenticated attacker operating
Remote code execution in the Windows Server Network driver stems from a race condition (CWE-362) that lets an unauthoriz
Remote code execution in Microsoft Windows Remote Desktop (RDP) allows an unauthorized network attacker to run arbitrary
Remote code execution in Microsoft Windows Message Queuing (MSMQ) allows an unauthenticated attacker to run arbitrary co
Same weakness CWE-121 – Stack-based Buffer Overflow
View allSame technique Buffer Overflow
View allShare
External POC / Exploit Code
Leaving vuln.today