Deploy the replacement for each Windows version instead: Windows 10, version 2004: KB5008212; Windows 10, version 20H2: KB5026361; Windows 10, version 21H1: KB5021233.
ChangeIntel's reading of public signals, not advice; check Microsoft's guidance and test before you deploy. Terms
Urgency Unknown · MSRC document not collectedRisk Moderate
MSRC's October 2021 security update document isn't collected, so the CVEs this update fixes are unknown. No known issues affecting this update, or resolved by it, were identified in the collected Windows release health data.
Applies to
From Microsoft's release-information tables
Servicing branch
OS build
Release
Available
Windows 10, version 21H1
19043.1288
B2021-10 B
12 Oct 2021
Windows 10, version 20H2
19042.1288
B2021-10 B
12 Oct 2021
Windows 10, version 2004
19041.1288
B2021-10 B
12 Oct 2021
What changed
Issues resolved: Unknown: known-issue evidence is incomplete or retained → None in the collected release health data · Known issues: Unknown: known-issue evidence is incomplete or retained → None in the collected release health data
Issues resolved: None in the collected release health data → Unknown: known-issue evidence is incomplete or retained · Known issues: None in the collected release health data → Unknown: known-issue evidence is incomplete or retained
Issues resolved: Unknown: known-issue evidence is incomplete or retained → None in the collected release health data · Known issues: Unknown: known-issue evidence is incomplete or retained → None in the collected release health data
Issues resolved: None in the collected release health data → Unknown: known-issue evidence is incomplete or retained · Known issues: None in the collected release health data → Unknown: known-issue evidence is incomplete or retained
Issues resolved: Unknown: known-issue evidence is incomplete or retained → None in the collected release health data · Known issues: Unknown: known-issue evidence is incomplete or retained → None in the collected release health data
Issues resolved: None in the collected release health data → Unknown: known-issue evidence is incomplete or retained · Known issues: None in the collected release health data → Unknown: known-issue evidence is incomplete or retained
Known issues: None in the collected release health data
Page history
Changes are dated when recorded; day views use the last saved version from that UTC day, and citations stay fixed.
Up to 100 recent field edits are shown; older edits may be outside retention.
7 Nov 2026 · 13:11:22 UTCKnown issues resolvedUnknown: known-issue evidence is incomplete or retained → None in the collected release health data
7 Nov 2026 · 13:11:22 UTCKnown issues affecting this updateUnknown: known-issue evidence is incomplete or retained → None in the collected release health data
7 Nov 2026 · 12:08:21 UTCKnown issues resolvedNone in the collected release health data → Unknown: known-issue evidence is incomplete or retained
7 Nov 2026 · 12:08:21 UTCKnown issues affecting this updateNone in the collected release health data → Unknown: known-issue evidence is incomplete or retained
6 Nov 2026 · 17:32:22 UTCKnown issues resolvedUnknown: known-issue evidence is incomplete or retained → None in the collected release health data
6 Nov 2026 · 17:32:22 UTCKnown issues affecting this updateUnknown: known-issue evidence is incomplete or retained → None in the collected release health data
6 Nov 2026 · 16:31:02 UTCKnown issues resolvedNone in the collected release health data → Unknown: known-issue evidence is incomplete or retained
6 Nov 2026 · 16:31:02 UTCKnown issues affecting this updateNone in the collected release health data → Unknown: known-issue evidence is incomplete or retained
5 Nov 2026 · 23:42:03 UTCKnown issues resolvedUnknown: known-issue evidence is incomplete or retained → None in the collected release health data
5 Nov 2026 · 23:42:03 UTCKnown issues affecting this updateUnknown: known-issue evidence is incomplete or retained → None in the collected release health data
5 Nov 2026 · 22:41:52 UTCKnown issues resolvedNone in the collected release health data → Unknown: known-issue evidence is incomplete or retained
5 Nov 2026 · 22:41:52 UTCKnown issues affecting this updateNone in the collected release health data → Unknown: known-issue evidence is incomplete or retained