Microsoft has released two additional Windows security updates that address the Spectre side-channel vulnerabilities that were revealed in January of 2018.
The latest updates (KB4091666 and KB4078407) are available as manual downloads and include microcode (or firmware) updates for various Intel CPUs, such as Broadwell, Haswell, Skylake and other chipsets. Updates are applicable for multiple Windows 10 and Windows Windows Server 2016 versions.
Both KB4091666 and KB4078407 address the Spectre Variant 2 “Branch Target Injection” (CVE 2017-5715).