Windows 10: Microcode updates KB4090007, KB4091663, KB4091664, KB4091666, KB4078407

Windows Update[German]Microsoft released the updates KB4090007, KB4091663, KB4091664, KB4091666 and KB078407 on April 24, 2018. These are microcode updates designed to protect Windows 10 against Spectre Variant 2 (and, if necessary, meltdown). Addition: The update  has also been released.


German site recognized some Microsoft kb articles about microcode updates released on April 24, 2018. Here are the links to the KB articles I found.

  • KB4090007 for Windows 10 Version 1709 uand Windows Server 2016 Version 1709
  • KB4091663 for Windows 10 Version 1703
  • KB4091664 for Windows 10 Version 1607 and Windows Server 2016
  • KB4091666 for Windows 10 Version 1507 (RTM)

Microsoft has now added microcode updates for Broadwell DE A1, Broadwell DE V1, Broadwell DE V2,V3, Broadwell DE Y0, Broadwell H 43e, Broadwell U/Y, Broadwell Xeon E3.

Product Names (CPU) Public Name CPUID Intel Microcode Update Revision Microsoft Update Standalone Package Version
Skylake H/S 6th Generation Intel Core Processor Family 506E3 0xC2 V2.001
Skylake U/Y & Skylake U23e 6th Generation Intel Core m Processors 406E3 0xC2 V2.001
Skylake Server SP (H0, M0, U0) Intel® Xeon® Bronze Processor 3104, 3106

Intel® Xeon® Gold Processor 5115, 5118, 5119T, 5120, 5120T, 5122, 6126, 6126F, 6126T, 6128, 6130, 6130F, 6130T, 6132, 6134, 6134M, 6136, 6138, 6138F, 6138T, 6140, 6140M, 6142, 6142F, 6142M, 6144, 6146, 6148, 6148F, 6150, 6152, 6154

Intel® Xeon® Platinum Processor 8153, 8156, 8158, 8160, 8160F, 8160M, 8160T, 8164, 8168, 8170, 8170M, 8176, 8176F, 8176M, 8180, 8180M

Intel® Xeon® Silver Processor 4108, 4109T, 4110, 4112, 4114, 4114T, 4116, 4116T

00050654 0x2000043 V2.001
Skylake D (Bakerville) Intel® Xeon® Processor D-2123IT, D-2141I, D-2142IT, D2143IT, D-2145NT, D-2146NT, D-2161I, D-2163IT, D2166NT, D-2173IT, D-2177NT, D-2183IT, D-2187NT 00050654 0x2000043 V2.001
Skylake X (Basin Falls) Intel® Core™ i9 79xxX, 78xxX 00050654 0x2000043 V2.001
Broadwell DE A1 Intel® Xeon® Processor D-1513N, D-1523N, D-1533N, D-1543N, D1553N 50665 0xE000009 V1.002
Broadwell DE V1 Intel® Xeon® Processor D-1520, D-1540 50662 0x15 V2.001
Broadwell DE V2,V3 Intel® Xeon® Processor D-1518, D-1519, D-1521, D-1527, D-1528, D-1531, D-1533, D-1537, D-1541, D-1548

Intel® Pentium® Processor D1507, D1508, D1509, D1517, D1519

50663 0x7000012 V2.001
Broadwell DE Y0 Intel® Xeon® Processor D-1557, D-1559, D-1567, D-1571, D-1577, D-1581, D-1587 50664 0xF000011 V2.001
Broadwell H 43e Intel® Core™ Processor i7-5950HQ, i7-5850HQ, i7-5750HQ, i7-5700HQ

Intel® Core™ Processor i5-5575R, i5-5675C, i5-5675R, i7-5775C, i7-5775R

Intel® Core™ Processor i7-5700EQ, i7-5850EQ

40671 0x1D V2.001
Broadwell U/Y Intel® Core™ Processor i7-5650U,i7-5600U, i7-5557U, i7-5550U, i7-5500U

Intel® Core™ Processor i5-5350U, i5-5350,i5-5300U, i5-5287U,i5-5257U, i5-5250U, i5-5200U

Intel® Core™ Processor i3-5157U, i3-5020U, i3-5015U, i3-5010U, i3-5006U, i3-5005U, i3-5010U, i5-5350U, i7-5650U

Intel® Core™ Processor M-5Y71, M-5Y70, M-5Y51, M-5Y3, M-5Y10c, M -5Y10a, M-5Y10

Intel® Pentium® Processor 3805U, 3825U, 3765U, 3755U, 3215U, 3205U

Intel® Celeron® 3765U

306D4 0x2A V2.001
Broadwell Xeon E3 Intel® Xeon® Processor v4 E3-1258L, E3-1265L, E3-1278L, E3-1285, E3-1285 40671 0x1D V2.001
Haswell (including H, S), Xeon E3 4th Generation Intel® Core™ Mobile Processor Family,

Intel® Pentium® Mobile Processor Family,

Intel® Celeron® Mobile Processor Family

306C3 0x24 V2.001
Haswell Perf Halo Intel® Core™ Extreme Processor (5960x, 5930x, 5820x) 40661 0x19 V2.001
Haswell Server E, EP, EP4S Intel® Xeon® Processor v3 E5-1428L, E5-1603, E5-1607, E5-1620, E5-1630, E5-1650, E5-1660, E5-1680, E5-2408L, E5-2418L, E5-2428L, E5-2438L, E5-2603, E5-2608L, E5-2608L, E5-2609, E5-2618L, E5-2620, E5-2623, E5-2628L, E5-2630, E5-2630L, E5-2637, E5-2640, E5-2643, E5-2648L, E5-2650, E5-2650L, E5-2658, E5-2660, E5-2667, E5-2670, E5-2680, E5-2683, E5-2685, E5-2687W,E5-2690, E5-2695, E5-2697, E5-2698, E5-2699, E5-4610, E5-4620, E5-4627, E5-4640, E5-4648, E5-4650, E5-4655, E5-4660, E5-4667, E5-4669 306F2 0x3C V2.001
Haswell ULT 4th Generation Intel® Core™ Mobile Processor Family,

Intel® Pentium® Mobile Processor Family,

Intel® Celeron® Mobile Processor Family

40651 0x23 V2.001

Here are the downloads from the Microsoft Update Catalog:

I did not find an update for Windows 10 version 1511. If you have not yet installed the Microcode updates, you can do so for the Windows 10 versions mentioned.

Notes: I gave the status of the microcode updates for Intel CPUs in the blog article Intel Spectre/Meltdown Microcode Updates (March 11, 2018). The difference between BIOS updates and Windows updates for microcodes is described in the article Microsoft Updates KB4091290/KB4090007/KB4052623 (March 1, 2018).

Spectre V2 update KB4078407

Microsoft also released a Spectre V2 update KB4078407 and wrote: Update to enable mitigation against Spectre, Variant 2. Applies to Windows 10 version 1709, Windows Server 2016 Version 1709 and Windows 10 Version 1703. Applying this update will enable the Spectre Variant 2 mitigation CVE-2017-5715 – "Branch target injection vulnerability."


The update is available via Microsoft Update Catalog. Microsoft write: Consult with your device manufacturer's and Intel's websites regarding their microcode recommendation for your device before applying this update to your device.

Cookies helps to fund this blog: Cookie settings

This entry was posted in Security, Update, Windows and tagged , , , , , , . Bookmark the permalink.

4 Responses to Windows 10: Microcode updates KB4090007, KB4091663, KB4091664, KB4091666, KB4078407

  1. Uplupa says:

    Any info about Sandy Bridge? Thanks

    • guenni says:

      The first source should be the Intel document linked within the text. Within my German blog post I received the following comment:

      Microsoft doesn't distribute the microcode updates for Sandy Bridge and Ivy Bridge. The performance impact is higher as for Haswell or newer.

  2. Pingback: Microsoft pushes more Spectre v2 microcode updates, KB 4090007, KB 4091663, KB 4091664 @ AskWoody

  3. EP says:

    The reason there is no new microcode update for Windows 10 v1511 is because that specific version is no longer supported. Microsoft dropped support for Win10 v1511 home/pro on October 10, 2017 and MS dropped support for Win10 v1511 education/enterprise on April 10, 2018.

Leave a Reply

Your email address will not be published. Required fields are marked *