dbcve.org
Windows 10 21h2Operating system · Microsoft

CVE-2025-27729

HIGH · 7.8 CVSS v3.1 Published 2025-04-08
Fix available
A fix is available. Upgrade to 10.0.19044.5737 / 10.0.19045.5737 or later.
See remediation →
81/100
Remediation priority · High
No privileges

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
Use after free in Windows Shell allows an unauthorized attacker to execute code 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

A use-after-free vulnerability in Windows Shell allows a local attacker to manipulate freed memory and achieve arbitrary code execution. The vulnerability stems from improper memory management in Shell components where object references are not properly invalidated after deallocation.

MitigationApply Microsoft security updates for Windows Shell when available. As interim compensating controls, restrict local access to trusted users only and monitor for suspicious processes interacting with Shell components.

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 21h2Operating system
Affected:< 10.0.19044.5737
Windows 10 22h2Operating system
Affected:< 10.0.19045.5737
Windows 11 22h2Operating system
Affected:< 10.0.22621.5189
Windows 11 23h2Operating system
Affected:< 10.0.22631.5189
Windows 11 24h2Operating system
Affected:< 10.0.26100.3775
Windows Server 2025Operating system
Affected:< 10.0.26100.3775

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
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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 10 21h2 build version
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' and locate the build number (e.g., 19044.xxxx)
    Affected if Build number is less than 19044.5737 on Windows 10 21h2 (check via winver: 10.0.19044.XXXX)
  2. Check Windows 10 22h2 build version
    Run 'winver' and note the 19045.xxxx build number
    Affected if Build number is less than 19045.5737 on Windows 10 22h2 (check via winver: 10.0.19045.XXXX)
  3. Check Windows 11 22h2 build version
    Run 'winver' and look for build 22621.xxxx
    Affected if Build number is less than 22621.5189 on Windows 11 version 22h2
  4. Check Windows 11 23h2 build version
    Run 'winver' and look for build 22631.xxxx
    Affected if Build number is less than 22631.5189 on Windows 11 version 23h2
  5. Check Windows 11 24h2 or Server 2025 build version
    Run 'winver' or 'systeminfo' and locate the 26100.xxxx build number
    Affected if Build number is less than 26100.3775 on Windows 11 24h2 or Windows Server 2025

Your environment is affected if the installed Windows build version is below the threshold listed for your specific Windows release (21h2, 22h2, 23h2, 24h2, or Server 2025) and the system uses Windows Shell (explorer.exe) which is the default on desktop and many server configurations.

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 10.0.19044.5737 / 10.0.19045.5737 / 10.0.22621.5189 or later
Fixed in 10.0.19044.573710.0.19045.573710.0.22621.5189
Interim mitigation

Apply Microsoft security updates for Windows Shell when available. As interim compensating controls, restrict local access to trusted users only and monitor for suspicious processes interacting with Shell components.

Recommended fix High confidence

Windows 10 21h2: 10.0.19044.5737 | Windows 10 22h2: 10.0.19045.5737 | Windows 11 22h2: 10.0.22621.5189 | Windows 11 23h2: 10.0.22631.5189 | Windows 11 24h2: 10.0.26100.3775 | Windows Server 2025: 10.0.26100.3775

  1. Open Settings > Windows Update and check for updates
  2. Install the cumulative update that brings your Windows version to the fixed release for your product
  3. Restart the computer when prompted to complete the installation
  4. Verify the update was applied by running 'winver' and confirming the build number matches or exceeds the fixed version for your Windows edition
Caveat Standard Windows update considerations - backup important data before applying updates

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

Fix this in Windows 10 21h2 Scoped from the published advisory
  • Consultation8.0 h
  • Implementation4.0 h
  • Testing12.0 h
  • Review / QA6.0 h
30.0 hours of engineering $5,200
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,320.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-27729 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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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-2025-27729 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