Windows 10 1607Operating system · Microsoft

CVE-2026-49178

HIGH · 8.8 CVSS v3.1 Published 2026-07-14
Fix available
A fix is available. Upgrade to 10.0.14393.9339 / 10.0.17763.9020 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click 5 weeks old

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 · unedited
Heap-based buffer overflow in Active Directory Domain Services allows an authorized attacker to execute code over a network.

In the news

Third-party coverage
Trending covered by 1 outlet this week · latest 1w ago

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 confidence

Heap-based buffer overflow vulnerability in Active Directory Domain Services. The flaw allows an authenticated attacker to overflow a heap-allocated buffer, potentially achieving remote code execution with the privileges of the targeted service.

MitigationApply vendor patches for Active Directory Domain Services immediately. Restrict network access to AD DS endpoints and enforce least-privilege access controls to minimize attack surface.

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
Windows 10 1607Operating system
Affected:< 10.0.14393.9339
Windows 10 1809Operating system
Affected:< 10.0.17763.9020
Windows 10 21h2Operating system
Affected:< 10.0.19044.7548
Windows 10 22h2Operating system
Affected:< 10.0.19045.7548
Windows 11 24h2Operating system
Affected:< 10.0.26100.8875
Windows 11 25h2Operating system
Affected:< 10.0.26200.8875
Windows 11 26h1Operating system
Affected:< 10.0.28000.2269< 10.0.28000.2525
Windows Server 2012Operating system
Affected:all versions= r2

CVSS 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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 checks

Work through these to decide whether this CVE applies to you.

  1. Confirm AD DS role is installed
    Run 'Get-WindowsFeature -Name AD-Domain-Services' in PowerShell on the target system, or check via Server Manager > Add Roles and Features. Look for 'Active Directory Domain Services' in the role list.
    Affected if The AD-Domain-Services role is installed and the server is functioning as a domain controller or has AD DS installed.
  2. Check installed Windows version
    Run 'winver' from the Run dialog, or execute 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' in Command Prompt, or use 'Get-ComputerInfo | Select-Object OsName, OsVersion' in PowerShell.
    Affected if The Windows version falls within any of these vulnerable ranges: Windows 10 1607 < 10.0.14393.9339, Windows 10 1809 < 10.0.17763.9020, Windows 10 21h2 < 10.0.19044.7548, Windows 10 22h2 < 10.0.19045.7548, Windows 11 24h2 < 10.0.26100.8875, Windows 11 25h2 < 10.0.26200.8875, Windows 11 26h1 < 10.0.28
  3. Verify AD DS service is running
    Run 'Get-Service -Name NTDS' in PowerShell. The NTDS service is the Active Directory Domain Services database engine. Alternatively, run 'sc query NTDS' from Command Prompt.
    Affected if The NTDS service exists and is in a Running state, indicating Active Directory Domain Services is active on this system.
  4. Confirm domain controller role
    Run '(Get-ADDomain).DomainMode' in PowerShell (requires Active Directory PowerShell module), or check System Information under 'Domain Controller' in the Computer System Summary, or run 'netdom query fsmo' to check for FSMO roles.
    Affected if The system responds as a domain controller or returns valid AD domain information, meaning this is a domain controller running AD DS.

A system is affected if it runs Windows 10/11 or Windows Server 2012 in the affected version ranges, has the Active Directory Domain Services role installed, and the NTDS service is running as a domain controller.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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.

From vendor data
Upgrade available Upgrade to 10.0.14393.9339 / 10.0.17763.9020 / 10.0.19044.7548 or later
Fixed in 10.0.14393.933910.0.17763.902010.0.19044.7548
Interim mitigation

Apply vendor patches for Active Directory Domain Services immediately. Restrict network access to AD DS endpoints and enforce least-privilege access controls to minimize attack surface.

Fix this in Windows 10 1607 Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA8.0 h
44.0 hours of engineering $7,720
Get the upgrade done

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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-49178 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-49178 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data