Integer overflow in Microsoft SQL Server - CVE-2026-77486
Published: September 9, 2026
Vulnerability identifier: #VU148418
CSH Severity: High
CVSS v4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-77486
CWE-ID: CWE-190
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to integer overflow or wraparound in the SQL Server client response-processing functionality when processing a response from a malicious server after a user connects to it. A remote attacker can host a malicious server and convince a user to connect to it to execute arbitrary code.
Affected software
Microsoft SQL Server
How to mitigate CVE-2026-77486
Install security update from vendor's website.
Microsoft SQL Server - addressed in versions 14.0.2130.4, 14.0.3550.4, 15.0.2190.7, 15.0.4490.9