What is CVE-2026-65815?

CVE-2026-65815 is a high-severity vulnerability in Microsoft Dynamics 365 (On-premises) Version 9.1, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2026-08-11.

How severe is CVE-2026-65815?

High severity. CVSS v3 base score is 8.8 out of 10.

Deserialization in Microsoft Dynamics 365 (On-premises) Version 9.1

CVE-2026-65815

Deserialization of untrusted data in Microsoft Dynamics 365 (on-premises) allows an authorized attacker to execute code over a network.

Vulnerability class: Insecure Deserialization

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Microsoft Dynamics 365 (On-premises) Version 9.1 — versions 9.0

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

secure@microsoft.com (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-65815?: CVE-2026-65815 is a high-severity vulnerability in Microsoft Dynamics 365 (On-premises) Version 9.1, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2026-08-11.
How severe is CVE-2026-65815?: High severity. CVSS v3 base score is 8.8 out of 10.