# CVE-2026-55944: Microsoft Dynamics NAV and Microsoft Dynamics 365 Business Central (On Premises) Remote Code Execution Vulnerability

> An unauthorized attacker can execute arbitrary code remotely by exploiting a deserialization flaw in Microsoft Dynamics NAV and Business Central.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Jul 2026
- **Updated:** 28 Oct 2026
- **Also known as:** GHSA-rvmx-r962-429w

## What is CVE-2026-55944?

CVE-2026-55944 is a critical unsafe deserialization vulnerability in Microsoft Dynamics NAV 2018, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-55944?

It affects 1 product.


Products: Microsoft Dynamics Nav.

## How do I fix CVE-2026-55944?

No fix has been published for CVE-2026-55944 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-55944 being exploited?

There is no known exploitation of CVE-2026-55944 in the wild and no public exploit code.

Public exploit code:

- This PoC simulates an XML parsing vulnerability where configuration data is parsed and passed directly to ProcessStartInfo. It extracts executable paths and arguments from XML markup to spawn a system process, demonstrating how unsafe input handling can lead to arbitrary command execution. (github_poc): https://github.com/kipkorirchirchir800-hash/Cve-2026-55944

## Other vulnerabilities in Microsoft Dynamics NAV 2018

- [CVE-2020-17133](https://insights.sbomify.com/CVE-2020-17133/): Microsoft Dynamics Business Central/NAV Information Disclosure Vulnerability (medium 6.5)
- [CVE-2018-8651](https://insights.sbomify.com/CVE-2018-8651/): Cross-site scripting in Microsoft Dynamics NAV (medium 5.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55944 and fix it if it is affected.

What it is: CVE-2026-55944 is a critical unsafe deserialization vulnerability in Microsoft Dynamics NAV 2018, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-55944 in the wild and no public exploit code.

Affected product: Microsoft Dynamics NAV 2018. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-55944/ (Markdown: https://insights.sbomify.com/CVE-2026-55944/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55944
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55944
- OSV: https://osv.dev/vulnerability/CVE-2026-55944

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-55944/
Summaries are generated and may contain mistakes; the official description above is the record.