Cyber Resilience

CVE-2026-55944

RCE in Microsoft Dynamics Nav 2018

Published
14 July 2026
Modified
22 July 2026
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.013 67th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-55944 is a critical-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Microsoft Dynamics Nav. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 33% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Deserialization of untrusted data enabling unauthenticated remote code execution over a network directly facilitates exploitation of public-facing applications.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-49712Same vendor: Microsoft
CVE-2026-40368Same vendor: Microsoft
CVE-2026-20963Same vendor: Microsoft
CVE-2025-59287Same vendor: Microsoft
CVE-2026-58644Same vendor: Microsoft
CVE-2025-59237Same vendor: Microsoft
CVE-2026-41104Same vendor: Microsoft
CVE-2026-26114Same vendor: Microsoft
CVE-2026-45659Same vendor: Microsoft
CVE-2026-26142Same vendor: Microsoft

Affected Assets

microsoft
dynamics nav
2018

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • AC-3 Access Enforcement
  • SI-3 Malicious Code Protection
Detect
Catch it (NIST detect / respond)
  • SI-3 Malicious Code Protection
Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly blocks deserialization of attacker-supplied data by enforcing validation of all inputs before processing.

prevent

Enforces access control so that only authorized subjects can reach the deserialization entry point over the network.

preventdetect

Malicious-code protection mechanisms can detect or block the payload that results from unsafe deserialization.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-02 none match
prevents

PR.PS-02 addresses only post-deployment updates/patching and cannot prevent introduction of unsafe deserialization code, yet it can remediate some instances when the flaw exists in outdated libraries or components.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing includes validation of deserialization routines and the use of untrusted data, reducing the likelihood that unsafe object reconstruction will be deployed.

prevents

Requiring vetted libraries, regular updates and SAST before release reduces the likelihood that deserialization logic will accept and act on attacker-controlled serialized objects.

detects

Regular scanning of third-party libraries and timely patching reduce the likelihood that unsafe deserialization vulnerabilities remain active.

none

Mandatory malware scanning of data received over networks or storage media intercepts malicious serialized payloads before they are deserialized by the target application.

References