CVE-2026-45647
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 · uneditedTime-of-check time-of-use (toctou) race condition in Microsoft Defender for Endpoint 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 confidenceA time-of-check time-of-use (TOCTOU) race condition in Microsoft Defender for Endpoint allows a locally authorized attacker to exploit a timing window between security state verification and its utilization, potentially achieving local privilege escalation.
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< 101.26042.0011CVSS 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
- High
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/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 checksWork through these to decide whether this CVE applies to you.
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Determine installed Microsoft Defender for Endpoint versionOpen Windows Security app, go to Settings > About, or run 'Get-MpComputerStatus' in PowerShell to retrieve the antivirus version detailsAffected if The installed version number is lower than 101.26042.0011
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Confirm Microsoft Defender for Endpoint is runningCheck if the Windows Defender service (MsMpEng.exe) or related Defender for Endpoint services are actively running on the systemAffected if Defender for Endpoint is installed and running on a version below 101.26042.0011
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Identify local user context and access levelReview local user accounts and their group memberships using 'net user' or 'Get-LocalUser' in PowerShellAffected if A user with some authorized access exists on the system running a vulnerable Defender for Endpoint version
If Microsoft Defender for Endpoint version is below 101.26042.0011 and the service is running, the system is potentially affected by this TOCTOU race condition vulnerability.
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 · scoped101.26042.0011
Apply Microsoft security updates for Defender for Endpoint when released; monitor vendor advisories for patch availability and prioritize deployment per organizational patch management policy.
Microsoft Defender for Endpoint version 101.26042.0011 or later
- 1. Verify current Microsoft Defender for Endpoint version by opening Windows Security > About or running 'msmpeng.exe -Version' in command prompt
- 2. If version is below 101.26042.0011, initiate the update process
- 3. Navigate to Microsoft Defender Security Center (securitycenter.microsoft.com)
- 4. Go to Settings > Device Management > Updates
- 5. Click 'Check for updates' or ensure automatic updates are enabled
- 6. Alternatively, use Microsoft Intune or Group Policy to deploy the latest Defender for Endpoint update
- 7. Restart endpoint if required after update installation
- 8. Verify the update was successful by checking the version number matches or exceeds 101.26042.0011
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,096.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-45647 — 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-2026-45647 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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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.
- 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
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