CVE-2026-55944
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 · uneditedDeserialization of untrusted data in Microsoft Dynamics NAV allows an unauthorized attacker to execute code over a network.
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 deserialization vulnerability in Microsoft Dynamics NAV where untrusted data being deserialized allows an unauthenticated attacker to execute arbitrary code over the network. Deserialization flaws occur when the application deserializes data without proper validation, potentially allowing attackers to manipulate serialized objects to inject malicious code.
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= 2018CVSS 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
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/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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Verify Microsoft Dynamics NAV installationLocate the Dynamics NAV installation by checking the Windows Program Files directory (typically C:\Program Files\Microsoft Dynamics NAV) or by querying installed programs via PowerShell: Get-ItemProperty 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\*' | Select-Object DisplayName, DisplayVersionAffected if Microsoft Dynamics NAV is present on the system
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Confirm exact version is 2018Check the specific version number of the installed Dynamics NAV. This can be done via the NAV Administration Shell (Get-NAVServerInstance -ServerInstance <instance>), by opening the Dynamics NAV Client and checking Help > About, or by examining the DLL version in the installation directoryAffected if The installed version is Microsoft Dynamics NAV 2018
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Identify exposed deserialization interfacesReview the NAV Server configuration to determine if OData V3/V4 endpoints, SOAP web services, or any API endpoints that handle data deserialization are enabled. Check the CustomSettings.config file (usually in C:\Program Files\Microsoft Dynamics NAV\<instance>\Service) for settings such as APIGatewayUrl, ODataServicesEnabled, or WebServicesEnabled set to trueAffected if Deserialization-capable endpoints (OData or SOAP web services) are enabled on the server
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Assess network accessibilityReview firewall rules and network configuration to determine if the affected NAV services (default ports 7045-7049 for the service tier, ports 8080/443 for web services) are exposed to untrusted networks or the internet. Use netstat -an | findstr 7045 or similar commands to identify listening portsAffected if NAV services handling deserialized data are reachable from untrusted or external networks without proper authentication barriers
An environment is affected if it runs Microsoft Dynamics NAV version 2018 with OData or SOAP web service endpoints that handle deserialization and are accessible to unauthenticated network attackers
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 vendor-provided security update for Microsoft Dynamics NAV immediately. Additionally, network segmentation and restricting unnecessary network exposure can reduce attack surface while patching.
- Consultation4.0 h
- Implementation16.0 h
- Testing12.0 h
- Review / QA8.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $11,072.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-55944 — 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-2026-55944 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