CVE-2026-45583
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 control of generation of code ('code injection') in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.
In the news
Third-party coverage- Microsoft June 2026 Patch Tuesday fixes 6 zero-days, 200 flaws
- 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 confidenceCode injection vulnerability in Microsoft Exchange Server that allows an unauthorized attacker to execute code over a network. The vulnerability stems from improper control of code generation, enabling remote code execution without authentication.
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< 15.02.2562.043CVSS 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
- Network
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:H/PR:N/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 installed Exchange Server versionRun 'Get-ExchangeServer | Format-List Name, AdminDisplayVersion' in Exchange Management Shell, or check the version via Control Panel > Programs and Features > Microsoft Exchange ServerAffected if The version matches Exchange 2016, Exchange 2019, or Subscription Edition versions earlier than 15.02.2562.043
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Verify external exposure of Exchange servicesReview firewall rules, reverse proxy configurations, or load balancer settings that expose OWA, ECP, EWS, and MAPI endpoints to untrusted networksAffected if Any of these Exchange services (OWA, ECP, EWS, MAPI) are accessible from external/untrusted networks without VPN or authentication gateway
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Inspect Exchange server logs for suspicious requestsReview IIS logs (typically in C:\inetpub\logs\LogFiles) and Exchange tracing logs for unusual patterns, especially in parameters related to code generation or script execution endpointsAffected if Logs show unexpected code-like strings in request parameters, or anomalous requests targeting Exchange web service endpoints
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Check for new or unexpected scheduled tasksUse Task Scheduler to review tasks created under Exchange service accounts, looking for tasks with unknown sources or unusual execution pathsAffected if New scheduled tasks exist that were not created by legitimate Exchange configuration
A user is affected if their Exchange Server version falls within the affected range (2016, 2019, or Subscription Edition < 15.02.2562.043) AND the Exchange web services are exposed to untrusted networks.
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 · scoped15.02.2562.043
Apply the Microsoft security patch for Exchange Server as soon as possible; if no patch is available, restrict network exposure and monitor for indicators of compromise.
Exchange Server 2016/2019: Latest Cumulative Update; Subscription Edition: 15.02.2562.043 or later
- Check current Exchange Server build version using Get-ExchangeServer | fl Name,AdminDisplayVersion
- For Exchange Server 2016 and 2019, obtain the latest Cumulative Update (CU) from microsoft.com/download/microsoft-exchange
- For Exchange Server Subscription Edition, update to version 15.02.2562.043 or later
- Apply the update during a maintenance window following Microsoft's documentation
- Verify the update was successful using the version check command
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,512.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-45583 — 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-2026-45583 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