Microsoft SQL Server Elevation of Privilege Vulnerability

I am running SQL Server on my system. What action do I need to take?
Update your relevant version of SQL Server using the applicable October 2026 security update listed below.
First, determine your SQL Server version number. For more information, see Microsoft Knowledge Base Article 321185 - How to determine the version, edition, and update level of SQL Server and its components., Second, locate the range containing your current version number in the following table. The corresponding update is the one you need to install.
5126967: 5126967, SQL Server 2025 CU9+GDR (October GDR 2026): SQL Server 2025 CU9+GDR (October GDR 2026), 17.0.5015.4: 17.0.5015.4, 17.0.4006.2 - 17.0.5005.3: 17.0.4006.2 - 17.0.5005.3, KB5122048 - SQL2025 RTM CU9: KB5122048 - SQL2025 RTM CU9, 5128492: 5128492, SQL Server 2025 RTM+GDR (October GDR 2026): SQL Server 2025 RTM+GDR (October GDR 2026), 17.0.1145.4: 17.0.1145.4, 17.0.1000.7 - 17.0.1135.8: 17.0.1000.7 - 17.0.1135.8, KB5122770 - Previous SQL2025 RTM GDR: KB5122770 - Previous SQL2025 RTM GDR, 5126934: 5126934, SQL Server 2022 CU27+GDR1 (October GDR 2026): SQL Server 2022 CU27+GDR1 (October GDR 2026), 16.0.4305.5: 16.0.4305.5, 16.0.4003.1 - 16.0.4295.3: 16.0.4003.1 - 16.0.4295.3, KB5104824 - SQL2022 RTM CU27: KB5104824 - SQL2022 RTM CU27, 5128493: 5128493, SQL Server 2022 RTM+GDR (October GDR 2026): SQL Server 2022 RTM+GDR (October GDR 2026), 16.0.1210.3: 16.0.1210.3, 16.0.1000.6 - 16.0.1200.5: 16.0.1000.6 - 16.0.1200.5, KB5122771 - Previous SQL2022 RTM GDR: KB5122771 - Previous SQL2022 RTM GDR, 5128494: 5128494, SQL Server 2019 CU32+GDR (October GDR 2026): SQL Server 2019 CU32+GDR (October GDR 2026), 15.0.4500.2: 15.0.4500.2, 15.0.4003.23 - 15.0.4490.9: 15.0.4003.23 - 15.0.4490.9, KB5122772 - Previous SQL2019 RTM CU32 GDR: KB5122772 - Previous SQL2019 RTM CU32 GDR, 5128495: 5128495, SQL Server 2019 RTM+GDR (October GDR 2026): SQL Server 2019 RTM+GDR (October GDR 2026), 15.0.2200.2: 15.0.2200.2, 15.0.2000.5 - 15.0.2190.7: 15.0.2000.5 - 15.0.2190.7, KB5122773 - Previous SQL2019 RTM GDR: KB5122773 - Previous SQL2019 RTM GDR, 5128496: 5128496, SQL Server 2017 CU31+GDR (October GDR 2026): SQL Server 2017 CU31+GDR (October GDR 2026), 14.0.3560.2: 14.0.3560.2, 14.0.3006.16 - 14.0.3550.4: 14.0.3006.16 - 14.0.3550.4, KB5122774 - Previous SQL2017 RTM CU31 GDR: KB5122774 - Previous SQL2017 RTM CU31 GDR, 5128497: 5128497, SQL Server 2017 RTM+GDR (October GDR 2026): SQL Server 2017 RTM+GDR (October GDR 2026), 14.0.2140.2: 14.0.2140.2, 14.0.1000.169 - 14.0.2130.4: 14.0.1000.169 - 14.0.2130.4, KB5122775 - Previous SQL2017 RTM GDR: KB5122775 - Previous SQL2017 RTM GDR
General Distribution Release (GDR) updates provide security and other broadly applicable critical fixes. Cumulative Updates (CUs) include accumulated fixes for the applicable SQL Server release. Use the version ranges above to select the security update for your installed servicing branch; CU+GDR updates apply to the listed CU branch, while RTM+GDR updates apply to the listed RTM/GDR branch.

According to the CVSS metric, the attack complexity is high (AC:H). What does this mean for this vulnerability?
An attacker would need specific conditions to be in place (i.e. particular protocol settings, or configurations, etc.) before an attack could succeed, which reduces the likelihood of widespread or opportunistic exploitation.

How could an attacker exploit this vulnerability?
An attacker who can execute code in a low-privilege AppContainer could exploit this vulnerability locally to escape the sandbox and elevate privileges on the affected system. No additional user interaction is required.

What privileges could be gained by an attacker who successfully exploited this vulnerability?
An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.

Security updates
14.0.3560.2 — https://support.microsoft.com/help/5128496
17.0.1145.4 — https://support.microsoft.com/help/5128492
14.0.2140.2 — https://support.microsoft.com/help/5128497
15.0.2200.2 — https://support.microsoft.com/help/5128495
15.0.4500.2 — https://support.microsoft.com/help/5128494
16.0.4305.5 — https://support.microsoft.com/help/5126934
17.0.5015.4 — https://support.microsoft.com/help/5126967
16.0.1210.3 — https://support.microsoft.com/help/5128493