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CVE-2026-55944 Microsoft CVE debrief

CVE-2026-55944 is a critical vulnerability in Microsoft Dynamics NAV that allows deserialization of untrusted data, enabling an unauthorized attacker to execute code over a network. The vulnerability has a CVSS score of 9.8 and is considered critical. Organizations must prioritize patching to prevent potential code execution attacks. This vulnerability exists due to insecure deserialization of untrusted data in Microsoft Dynamics NAV, allowing attackers to exploit via malicious data sent over the network.

Vendor
Microsoft
Product
Microsoft Dynamics NAV 2018
CVSS
CRITICAL 9.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-14
Original CVE updated
2026-07-22
Advisory published
2026-07-14
Advisory updated
2026-07-22

Who should care

Organizations using Microsoft Dynamics NAV should prioritize patching this vulnerability to prevent potential code execution attacks. Security teams and vulnerability management teams should review and update affected systems, and monitor for suspicious activity.

Technical summary

The vulnerability exists in Microsoft Dynamics NAV due to insecure deserialization of untrusted data. An attacker can exploit this vulnerability by sending malicious data over the network, potentially leading to code execution. This issue has a CVSS score of 9.8, indicating critical severity. Affected organizations should apply patches and monitor for suspicious activity.

Defensive priority

High

Recommended defensive actions

  • Apply the vendor patch
  • Review and update affected systems
  • Monitor for suspicious activity
  • Review compensating controls for exposed systems
  • Check relevant monitoring, detection, and logs for exposed assets

Evidence notes

The CVE record was published on 2026-07-14T18:18:21.850Z and was last modified on 2026-07-22T16:42:03.610Z. The NVD entry is currently Analyzed. This vulnerability affects Microsoft Dynamics NAV, enabling deserialization of untrusted data which could lead to code execution. Evidence is based on CVE and NVD entries, which may have limited detail. Defenders should verify affected systems and review vendor advisories for specific guidance.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-14T18:18:21.850Z and has not been modified since then. The NVD entry is currently Analyzed.