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.

← Nov 2025 Jan 2026 →

Superseded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 · January 2031

Wed 1 Jan

Thu 2 Jan

Fri 3 Jan

Sat 4 Jan

Sun 5 Jan

Mon 6 Jan

Tue 7 Jan

Wed 8 Jan

Thu 9 Jan

Fri 10 Jan

Sat 11 Jan

Sun 12 Jan

Mon 13 Jan

Tue 14 Jan

Patch Tuesday

Wed 15 Jan

Thu 16 Jan

Fri 17 Jan

Sat 18 Jan

Sun 19 Jan

Mon 20 Jan

Tue 21 Jan

Wed 22 Jan

Thu 23 Jan

Fri 24 Jan

Sat 25 Jan

Sun 26 Jan

Mon 27 Jan

Tue 28 Jan

Wed 29 Jan

Thu 30 Jan

Fri 31 Jan

Patch Tuesday and security (B) releasesPreview (D) releasesOut-of-band releases.NET Framework servicing packagesEdge, Office, Teams, Defender and server releasesAll product versions