What is CVE-2026-55944?

CVE-2026-55944 is a critical-severity vulnerability in Microsoft Dynamics Nav, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2026-07-14.

How severe is CVE-2026-55944?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Deserialization in Microsoft Dynamics Nav

CVE-2026-55944

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

Vulnerability class: Insecure Deserialization

Published 2026-07-14 · last modified 2026-07-22.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.015 (74.6th percentile), scored 2026-10-24.

Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 74.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.015 · newest: 0.015 · change: 0.000

Affected products

Microsoft Dynamics Nav — versions 2018
Microsoft Dynamics Nav 2018 — versions 1.0

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

Microsoft Dynamics NAV and Microsoft Dynamics 365 Business Central (On Premises) Remote Code Execution Vulnerability (vendor-advisory, Patch, patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-55944?: CVE-2026-55944 is a critical-severity vulnerability in Microsoft Dynamics Nav, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2026-07-14.
How severe is CVE-2026-55944?: Critical severity. CVSS v3 base score is 9.8 out of 10.