CVE-2026-55006
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 · uneditedInsufficient granularity of access control in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.
In the news
Third-party coverage- Microsoft July 2026 Patch Tuesday fixes massive 570 flaws, 3 zero-days
- Microsoft CVE Summary - Bleeping Computer
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 confidenceThis is a local privilege escalation vulnerability in Microsoft Exchange Server stemming from insufficient granularity of access control. An attacker who already has authorized access to the system can exploit the overly broad permission model to elevate their privileges to higher-level accounts or roles within the Exchange environment.
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= 2016= 2019< 15.02.2562.045CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify the installed Exchange Server versionUse the Exchange Management Shell or check the installed programs to determine the exact version number of Microsoft Exchange ServerAffected if The installed version is Exchange Server 2016, Exchange Server 2019, or Exchange Server Subscription Edition with build number less than 15.02.2562.045
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Confirm local access capability existsVerify that the system allows local interactive logon or remote desktop access for non-administrative usersAffected if Users with standard accounts can access the Exchange server locally or via remote sessions, providing a potential attack surface for privilege escalation
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Review Exchange role group membershipsExamine the membership of Exchange Administrator role groups using Get-RoleGroupMember cmdlet in Exchange Management ShellAffected if Users with lower-privilege Exchange roles exist alongside higher-privilege role groups, indicating the broad permission model that could be exploited for escalation
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Check service account configurationsReview the service accounts configured for Exchange services and their assigned permissionsAffected if Exchange service accounts have been granted broader permissions than necessary, creating potential privilege escalation paths
You are affected if your Exchange Server version matches 2016, 2019, or Subscription Edition with build below 15.02.2562.045 AND non-administrative users have local access to the server, enabling exploitation of the overly broad access control model.
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 data15.02.2562.045
Apply Microsoft security updates for Exchange Server immediately when available; review and implement the principle of least privilege for Exchange service accounts and administrative roles; audit existing user permissions and role group memberships to limit privilege escalation paths.
- Consultation6.0 h
- Implementation8.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,296.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-55006 — 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-2026-55006 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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- 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