CVE-2026-50304
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedStack-based buffer overflow in Active Directory Federation Services allows an unauthorized attacker to deny service over a network.
In the news
Third-party coverage- Microsoft July 2026 Patch Tuesday fixes massive 570 flaws, 3 zero-days
- Microsoft CVE Summary - Bleeping Computer
Surfaced from public web coverage — external links open in a new tab.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceA stack-based buffer overflow vulnerability exists in Active Directory Federation Services (ADFS) that allows an unauthenticated remote attacker to cause a denial of service by overflowing a stack buffer.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 10.0.14393.9339< 10.0.17763.9020all versions= r2< 10.0.14393.9339< 10.0.17763.9020< 10.0.20348.5386< 10.0.26100.33158CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Verify ADFS is installedOn Windows Server, run Get-WindowsFeature | Where-Object {$_.Name -like '*ADFS*' -or $_.DisplayName -like '*Federation*'} to list ADFS-related features. On Windows 10, check Program Files for ADFS components or review installed programs for 'Active Directory Federation Services'.Affected if ADFS is not installed on the system, the vulnerability does not apply.
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Confirm ADFS service is runningRun Get-Service adfssrv or Get-Service | Where-Object {$_.Name -like '*ADFS*'} to check if any ADFS service is present and running.Affected if No ADFS service is running, the attack surface is not exposed.
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Identify Windows versionRun 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to determine the exact Windows version and build number.Affected if The version is NOT in any of these ranges: Windows 10 1607 (build < 14393.9339), Windows 10 1809 (build < 17763.9020), Windows Server 2012 (any), Windows Server 2012 R2 (any), Windows Server 2016 (build < 14393.9339), Windows Server 2019 (build < 17763.9020), Windows Server 2022 (build < 20348.5386)
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Check ADFS configuration for network exposureReview ADFS endpoints via Get-AdfsEndpoint in PowerShell (if ADFS is installed) to confirm which network bindings and ports are enabled. Check firewall rules for ports 443, 49443 (typical ADFS ports).Affected if ADFS is accessible from untrusted networks, an unauthenticated attacker could reach the vulnerable component.
A system is affected only if it runs ADFS (installed and service active), is a vulnerable Windows version listed in the affected ranges, and has ADFS network endpoints exposed to potential attackers.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped10.0.14393.933910.0.17763.902010.0.20348.5386
Apply the appropriate Microsoft security update for ADFS when available, and consider network segmentation and rate limiting as interim protective measures.
Upgrade to the minimum fixed build for your Windows version: 10.0.14393.9339 (1607/Server 2016), 10.0.17763.9020 (1809/Server 2019), 10.0.20348.5386 (Server 2022), or 10.0.26100.33158 (Server 2025)
- Identify the current Windows version and build number by running 'winver' or 'systeminfo'
- Determine which Windows 10 or Server version is currently deployed from the affected list
- For Windows Server 2012/2012 R2: Plan migration to a supported Windows Server version as these products have reached end of support
- For Windows 10 1607 systems: Upgrade to Windows 10 build 10.0.14393.9339 or later via Windows Update or your organization's update infrastructure
- For Windows 10 1809 systems: Upgrade to Windows 10 build 10.0.17763.9020 or later
- For Windows Server 2016 systems: Upgrade to build 10.0.14393.9339 or later through Windows Server Update Services (WSUS) or Windows Update
- For Windows Server 2019 systems: Upgrade to build 10.0.17763.9020 or later
- For Windows Server 2022 systems: Upgrade to build 10.0.20348.5386 or later
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-50304 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-50304 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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