CVE-2026-66818 Microsoft SQL Server Elevation of Privilege Vulnerability

High 8.8 Published 8 Sep 2026 Updated 14 Oct 2026

An authorized attacker can elevate privileges over the network due to improper privilege management in Microsoft SQL Server.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-66818?

CVE-2026-66818 is a high-severity vulnerability in Microsoft Sql Server 2017, published on 8 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Improper privilege management in SQL Server allows an authorized attacker to elevate privileges over a network.

Weakness: CWE-269

Which versions are affected by CVE-2026-66818?

It affects 4 products.

Products include Microsoft Sql Server 2017, Microsoft Sql Server 2019, Microsoft Sql Server 2022, Microsoft Sql Server 2025.

How do I fix CVE-2026-66818?

No fix has been published for CVE-2026-66818 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-66818 being exploited?

There is no known exploitation of CVE-2026-66818 in the wild and no public exploit code.

All Microsoft Sql Server 2017 vulnerabilities

Sources

Also known as GHSA-hx68-h5c3-vvjp.