SummaryImproper certificate validation in Visual Studio allows an unauthorized attacker to perform spoofing over a network.RemediationInventory every Microsoft Microsoft Visual Studio 2017 version 15.9 deployment, including staging.Upgrade Microsoft Microsoft Visual Studio 2017 version 15.9 to the fixed version for your release line, listed under Affected versions.Confirm the running version after the upgrade.ReferencesPatchhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-118147