Tuesday 9 December 2025
December 2025: 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.
Superseded
Newer updates replace December 2025.
The CVEs it fixes are unknown; no open known issues found in the current public evidence; out-of-band fixes followed on 18 Dec. See November 2026 Patch Tuesday.
MSRC's December 2025 security update document isn't collected.
ChangeIntel's reading of public signals, not advice; check Microsoft's guidance and test before you deploy. Terms
- Microsoft CVEs
- Unknown
- Exploited fixed
- Unknown
- In CISA KEV
- Unknown
- Open known issues
- 0
- Out-of-band
- 3
Release calendar · May 2030
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Patch Tuesday and security (B) releasesPreview (D) releasesOut-of-band releases.NET Framework servicing packagesEdge, Office, Teams, Defender and server releasesAll product versions