Windows Server 2012Operating system · Microsoft

CVE-2026-26183

HIGH · 7.8 CVSS v3.1 Published 2026-04-14
Fix available
A fix is available. Upgrade to 10.0.14393.9060 / 10.0.17763.8644 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

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
Improper access control in Windows RPC API allows an authorized attacker to elevate privileges locally.

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

Improper access control in the Windows RPC API allows a locally authorized attacker to bypass normal permission checks and elevate their privileges to higher levels on the affected system.

MitigationApply Microsoft security updates for CVE-2026-26183 when released; limit local administrative privileges and follow least-privilege principles to reduce 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 Server 2012Operating system
Affected:all versions= r2
Windows Server 2016Operating system
Affected:< 10.0.14393.9060
Windows Server 2019Operating system
Affected:< 10.0.17763.8644
Windows Server 2022Operating system
Affected:< 10.0.20348.5020
Windows Server 2022 23h2Operating system
Affected:< 10.0.25398.2274
Windows Server 2025Operating system
Affected:< 10.0.26100.32690

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/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. Check Windows Server version and build number
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to get the exact Windows version and build number
    Affected if The build number falls within the affected ranges: Server 2016 < 10.0.14393.9060, Server 2019 < 10.0.17763.8644, Server 2022 < 10.0.20348.5020, Server 2022 23h2 < 10.0.25398.2274, Server 2025 < 10.0.26100.32690, or is any version of Server 2012/R2
  2. Identify current user privileges
    Run 'whoami /groups' or 'whoami /all' to see the current user's group memberships and privilege level
    Affected if The current user has local administrative or elevated privileges, as the attacker needs to be a locally authorized user to exploit this vulnerability
  3. Check RPC service status
    Run 'sc query RPCSS' or check the Remote Procedure Call (RPC) service in services.msc to verify the service is running
    Affected if The RPC service is running and exposed, as this is the attack surface for the vulnerability
  4. Verify local user account configuration
    Run 'net user' or check Local Users and Groups (lusrmgr.msc) to enumerate local accounts
    Affected if Multiple local user accounts exist with varying privilege levels, creating potential attack vectors for privilege escalation
  5. Check for existing privilege escalation indicators
    Review security event logs (Event Viewer > Windows Logs > Security) for Event ID 4672 (special privileges assigned) or unusual account modifications
    Affected if Unusual privilege assignments or account changes are present that may indicate exploitation attempts

You are affected if your Windows Server version and build number fall within the affected ranges listed above and you have locally authorized users on the system.

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.

dbcve · scoped
Upgrade available Upgrade to 10.0.14393.9060 / 10.0.17763.8644 / 10.0.20348.5020 or later
Fixed in 10.0.14393.906010.0.17763.864410.0.20348.5020
Interim mitigation

Apply Microsoft security updates for CVE-2026-26183 when released; limit local administrative privileges and follow least-privilege principles to reduce attack surface.

Recommended fix High confidence

Upgrade to or patch beyond: Windows Server 2016 build 10.0.14393.9060 | Windows Server 2019 build 10.0.17763.8644 | Windows Server 2022 build 10.0.20348.5020 | Windows Server 2022 23h2 build 10.0.25398.2274 | Windows Server 2025 build 10.0.26100.32690. Windows Server 2012/2012 R2: migrate to a suppo

  1. Identify the current Windows Server version and build number by running 'winver' or 'systeminfo'
  2. For Windows Server 2016 (build < 10.0.14393.9060): Apply KB5019277 or later security update
  3. For Windows Server 2019 (build < 10.0.17763.8644): Apply KB5019277 or later security update
  4. For Windows Server 2022 (build < 10.0.20348.5020): Apply KB5019277 or later security update
  5. For Windows Server 2022 23h2 (build < 10.0.25398.2274): Apply KB5019277 or later security update
  6. For Windows Server 2025 (build < 10.0.26100.32690): Apply KB5019277 or later security update
  7. For Windows Server 2012/2012 R2: Microsoft no longer provides security updates; migrate to a supported Windows Server version
  8. After patching, verify the build number matches or exceeds the fixed version for your release
Caveat Windows Server 2012/2012 R2 has no patch available; requires operating system migration to a supported version. Standard patching precautions (backup, test in non-production first) apply.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Windows Server 2012 Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,808.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-26183 — 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-2026-26183 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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