September 2026: is it safe to deploy?
What Microsoft fixed, how urgent it is, and whether anything broke, per Windows version, from Microsoft's release tables, release health, MSRC, CISA, and what the community reports.
Newer updates replace September 2026.
Microsoft fixed 998 CVEs, 132 critical and 2 exploited; no open known issues found in the current public evidence; out-of-band fixes followed on 14 Sep. See November 2026 Patch Tuesday.
26 of these CVEs were added after 8 Sep 2026; the release-day timeline keeps the original publication dates.
ChangeIntel's reading of public signals, not advice; check Microsoft's guidance and test before you deploy. Terms
What to deploy, per Windows version
All 12 versions:SupersededUrgency: Critical · 1 exploitedRisk: ModerateFixes 1 exploited vulnerability; CISA deadline 22 SepNo known issues linked to this update were identified in the collected Windows release health data
Verdicts read public signals for each update: fixed CVEs and their exploitation, known issues, and out-of-band follow-ups. Open an update for every reason and its builds.
.NET Framework updates
Framework servicing updates are separate from the Windows OS updates above. Open a KB for its applicability, related packages, and security improvements.