CVE-2025-26685
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 · uneditedImproper authentication in Microsoft Defender for Identity allows an unauthorized attacker to perform spoofing over an adjacent network.
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 · high confidenceMicrosoft Defender for Identity contains an improper authentication vulnerability that allows an unauthorized attacker on an adjacent network to perform spoofing attacks. The product fails to properly validate authentication, enabling attackers to impersonate legitimate users or systems within the network proximity.
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 dataall versionsCVSS 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
- Adjacent
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
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 Microsoft Defender for Identity is installedCheck the installed applications or services on the system for 'Microsoft Defender for Identity' or 'Azure Advanced Threat Protection' (the product's former name). In PowerShell: Get-WmiObject -Class Win32_Product | Where-Object {$_.Name -match 'Defender for Identity'} or check services list.Affected if The product appears in installed programs or services list
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Check Defender for Identity service statusOpen Services.msc and look for 'Microsoft Defender for Identity' service, or run Get-Service -Name '*Defender*Identity*' in PowerShell to confirm the service exists and is running.Affected if The service exists and is running (indicating the product is active in the environment)
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Confirm the installation versionNavigate to the Defender for Identity sensor installation directory (typically C:\Program Files\Microsoft Defender for Identity\) and locate the sensor version information, or check in the Defender for Identity portal under sensor management.Affected if Any version is returned - all versions of Microsoft Defender for Identity are affected per CVE-2025-26685
If Microsoft Defender for Identity is installed and running in the environment, the system is affected by this improper authentication vulnerability that allows adjacent network attackers to perform spoofing attacks.
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.
From vendor dataApply the Microsoft security update for CVE-2025-26685 to Microsoft Defender for Identity. Verify the patch does not interfere with the product's detection and monitoring capabilities.
- 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-2025-26685 — 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-2025-26685 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
- No spam, self-promotion, credentials, or personal data