Microsoft Dynamics NAV 2018: unsafe deserialization

Microsoft Dynamics NAV 2018

Deserialization of untrusted data in Microsoft Dynamics NAV allows an unauthorized attacker to execute code over a network.

Fix it

Upgrade to Microsoft Dynamics NAV 2018 11.0.50704.0

First seen: 27 Oct 2026
Last update: 27 Oct 2026, 03:17 UTC
Fixed in: 11.0.50704.0
Identifiers: CVE-2026-55944
CVSS: 9.8
Source: news

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## Microsoft Dynamics NAV 2018: unsafe deserialization
Severity: critical. Patch status: patched.
Affected: Microsoft Dynamics NAV 2018
Fixed in: 11.0.50704.0
Ids: CVE-2026-55944

Deserialization of untrusted data in Microsoft Dynamics NAV allows an unauthorized attacker to execute code over a network.

## Steps
1. Search the repo, its CI and infra config for Microsoft Dynamics NAV 2018. If present, report the version in use and whether it's affected.
2. Fix by release line: Microsoft Dynamics NAV 2018: 11.0.50704.0.

## Fix by release line
| Line | State | Fix | Until then |
|---|---|---|---|
| Microsoft Dynamics NAV 2018 | fixed | 11.0.50704.0 | — |

## Report
A table: file, product or package, version in use, affected yes/no, exact fix. Then anything a human has to check outside the repo.

If you have the pwned.coffee MCP server (https://pwned.coffee/mcp), call lookup_cve("CVE-2026-55944") for the latest, and check_repo with this repo's lockfiles, Dockerfiles and workflows for a full receipt.
Sources: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55944 https://nvd.nist.gov/vuln/detail/CVE-2026-55944
https://pwned.coffee/i/deserialization-of-untrusted-data-in-microsoft-dynamics-cve-2026-55944

Timeline

27 Oct 2026, 03:18 UTC
Fix status: unknown → patched.
27 Oct 2026
First reported.

Receipt

Exploitation: No known exploitation
Fix by release line: Product Affected Fixed in Source
Microsoft Dynamics NAV 2018 before 11.0.50704.0 11.0.50704.0 CVE record (CNA) checked 27 Oct
Score: CVSS 9.8 (critical). CVSS 3.1 9.8 (CNA microsoft) for CVE-2026-55944
Last checked: 27 Oct 2026, 03:18 UTC

Product	Affected	Fixed in	Source
Microsoft Dynamics NAV 2018	before 11.0.50704.0	11.0.50704.0	CVE record (CNA) checked 27 Oct

Sources: KEV – CVE record ✓ Vendor ✓

Sources

Wrong fix version, or a source we missed? Send it back to chef@pwned.coffee with the source, and we'll correct it here.

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