EUVD-2026-44118
GHSA-wcpq-cwvv-7pj4
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Network-reachable AD FS endpoint, no auth or interaction, low-complexity infinite-loop trigger; availability-only impact with no confidentiality or integrity loss and 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
Loop with unreachable exit condition ('infinite loop') in Active Directory Federation Services (AD FS) allows an unauthorized attacker to deny service over a network.
AnalysisAI
Denial of service in Microsoft Active Directory Federation Services (AD FS) allows an unauthenticated, remote attacker to send crafted network requests that drive a request-handling routine into an infinite loop (CWE-835), exhausting CPU and rendering the federation service unavailable. All supported Windows Server releases hosting the AD FS role are impacted, and because the flaw requires no authentication and no user interaction (CVSS 7.5, AV:N/AC:L/PR:N/UI:N), it can knock out single sign-on for every relying-party application. …
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 | The only hard prerequisite is network reachability of an AD FS service endpoint; per the CVSS vector (AV:N/AC:L/PR:N/UI:N) there is no authentication, no privileges, and no user interaction required, so any actor able to send requests to the AD FS token/federation endpoint can attempt the attack against a default AD FS deployment. … 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, base 7.5) is internally consistent for a pure availability attack: network reachable, low complexity, no privileges, no user interaction, high availability impact, and no confidentiality or integrity loss. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An unauthenticated attacker who can reach an AD FS endpoint over the network (directly or through an exposed Web Application Proxy) sends a specially crafted request that trips the flawed processing loop, pinning a worker thread at 100% CPU. Repeating this a handful of times exhausts the service's thread pool, causing token issuance to hang and taking down single sign-on for all dependent applications. … |
| Remediation | Patch available per vendor advisory: apply the Microsoft security update for CVE-2026-50647 to every affected Windows Server (and, where the shared component is present, client) build via the MSRC guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50647, which lists the exact fixed build number for each product - install the update on all AD FS servers in the farm and reboot as required. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, identify all Windows Server instances hosting the AD FS role and determine their current patch status; establish a maintenance window and service recovery procedure. …
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 technique Denial Of Service
View allShare
External POC / Exploit Code
Leaving vuln.today