Patch today
Exploited in the wild
Confirmed attacks are already happening. Emergency change window.
No actively exploited vulnerabilities in this release.
Microsoft's December 2023 Patch Tuesday fixes 35 vulnerabilities across Windows, Azure and Microsoft Dynamics - 4 rated Critical, 1 publicly disclosed before the patch shipped. No active exploitation this month, so lead with the 3 Critical remote code execution fixes.
Why this number differs from other roundups. Microsoft's December 2023 release document lists 116 entries. 65 are Azure Linux (Mariner) OS package updates and 16 are republished Chromium fixes for Edge - neither is a Microsoft product vulnerability. The 35 above is the real Patch Tuesday set. See the breakdown →
Ranked by exploitation reality, not score alone. Nothing is under active attack this month, so the Critical remote-code-execution fixes lead.
Patch today
Confirmed attacks are already happening. Emergency change window.
No actively exploited vulnerabilities in this release.
Patch this week
Details are already public. Working exploits typically follow within days.
CVE-2023-20588AMD: CVE-2023-20588 AMD Speculative Leaks Security NoticePatch this cycle
No known exploitation yet, but network-reachable and high impact.
CVE-2023-35641Internet Connection Sharing (ICS) Remote Code Execution VulnerabilityCVE-2023-35628Windows MSHTML Platform Remote Code Execution VulnerabilityCVE-2023-35630Internet Connection Sharing (ICS) Remote Code Execution VulnerabilitySee all 4 Critical →Most roundups quote a single number. These are three unrelated release streams.
Microsoft channel only · 35 CVEs
| Critical | 4 |
|---|---|
| Important | 31 |
| Moderate | 0 |
| Low | 0 |
What an attacker gains if it works
| Elevation of Privilege | 10 |
|---|---|
| Remote Code Execution | 8 |
| Information Disclosure | 6 |
| Spoofing | 6 |
| Denial of Service | 5 |
Where this month’s fixes concentrate - filter by any of them in the table below
Sorted by risk by default: exploited first, then publicly disclosed, then severity, then CVSS. Search by CVE, title, component or KB number.
| Title | Status | KB | |||||
|---|---|---|---|---|---|---|---|
| Important | CVE-2023-20588 | AMD: CVE-2023-20588 AMD Speculative Leaks Security Notice | Info Disc. | - | Disclosed | Chipsets | 5033118 +14 |
| Critical | CVE-2023-35641 | Internet Connection Sharing (ICS) Remote Code Execution Vulnerability | RCE | 8.8 | More likely | Windows Internet Connection Sharing (ICS) | 5033118 +14 |
| Critical | CVE-2023-35628 | Windows MSHTML Platform Remote Code Execution Vulnerability | RCE | 8.1 | More likely | Windows MSHTML Platform | 5033118 +13 |
| Important | CVE-2023-35631 | Win32k Elevation of Privilege Vulnerability | EoP | 7.8 | More likely | Windows Win32K | 5033369 +2 |
| Important | CVE-2023-35632 | Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability | EoP | 7.8 | More likely | Windows Internet Connection Sharing (ICS) | 5033371 +7 |
| Important | CVE-2023-35633 | Windows Kernel Elevation of Privilege Vulnerability | EoP | 7.8 | More likely | Windows Kernel | 5033379 +6 |
| Important | CVE-2023-35644 | Windows Sysmain Service Elevation of Privilege Vulnerability | EoP | 7.8 | More likely | Windows Kernel-Mode Drivers | 5033118 +6 |
| Important | CVE-2023-36011 | Win32k Elevation of Privilege Vulnerability | EoP | 7.8 | More likely | Windows Win32K | 5033118 +10 |
| Important | CVE-2023-36391 | Local Security Authority Subsystem Service Elevation of Privilege Vulnerability | EoP | 7.8 | More likely | Windows Local Security Authority Subsystem Service (LSASS) | 5033375 |
| Important | CVE-2023-36696 | Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability | EoP | 7.8 | More likely | Windows Cloud Files Mini Filter Driver | 5033118 +6 |
| Important | CVE-2023-36005 | Windows Telephony Server Elevation of Privilege Vulnerability | EoP | 7.5 | More likely | Windows Telephony Server | 5033118 +14 |
| Important | CVE-2023-36010 | Microsoft Defender Denial of Service Vulnerability | DoS | 7.5 | More likely | Windows Defender | — |
| Critical | CVE-2023-36019 | Microsoft Power Platform Connector Spoofing Vulnerability | Spoofing | 9.6 | — | Microsoft Power Platform Connector | — |
| Critical | CVE-2023-35630 | Internet Connection Sharing (ICS) Remote Code Execution Vulnerability | RCE | 8.8 | — | Windows Internet Connection Sharing (ICS) | 5033118 +14 |
| Important | CVE-2023-35639 | Microsoft ODBC Driver Remote Code Execution Vulnerability | RCE | 8.8 | — | Windows ODBC Driver | 5033118 +14 |
| Important | CVE-2023-36006 | Microsoft WDAC OLE DB provider for SQL Server Remote Code Execution Vulnerability | RCE | 8.8 | — | Microsoft WDAC OLE DB provider for SQL | 5033118 +14 |
| Important | CVE-2023-35634 | Windows Bluetooth Driver Remote Code Execution Vulnerability | RCE | 8.0 | — | Microsoft Bluetooth Driver | 5033369 +1 |
| Important | CVE-2023-21740 | Windows Media Remote Code Execution Vulnerability | RCE | 7.8 | — | Windows Media | 5033118 +12 |
| Important | CVE-2023-36020 | Microsoft Dynamics 365 (on-premises) Cross-site Scripting Vulnerability | Spoofing | 7.6 | — | Microsoft Dynamics | 5032297 +1 |
| Important | CVE-2023-35621 | Microsoft Dynamics 365 Finance and Operations Denial of Service Vulnerability | DoS | 7.5 | — | Microsoft Dynamics | — |
| Important | CVE-2023-35622 | Windows DNS Spoofing Vulnerability | Spoofing | 7.5 | — | Microsoft Windows DNS | 5033118 +10 |
| Important | CVE-2023-35638 | DHCP Server Service Denial of Service Vulnerability | DoS | 7.5 | — | Windows DHCP Server | 5033118 +6 |
| Important | CVE-2023-35643 | DHCP Server Service Information Disclosure Vulnerability | Info Disc. | 7.5 | — | Windows DHCP Server | 5033118 +6 |
| Important | CVE-2023-36004 | Windows DPAPI (Data Protection Application Programming Interface) Spoofing Vulnerability | Spoofing | 7.5 | — | Windows DPAPI (Data Protection Application Programming Interface) | 5033118 +14 |
| Important | CVE-2023-35624 | Azure Connected Machine Agent Elevation of Privilege Vulnerability | EoP | 7.3 | — | Azure Connected Machine Agent | — |
The same five steps every month, in the order that reduces risk fastest.
Nothing is under active attack this month, so rank by exploitability forecast and reachability rather than raw score. A Critical flaw on an internet-facing service outranks a higher-scoring one behind authentication.
Patch Management vs Vulnerability Management: What's the Difference? →This release means 20 distinct update packages to deploy. Pilot on ring 0 within 24 hours and widen to production by day seven - never push the whole set everywhere at once.
What is Ring-Based Patch Deployment? A Guide to Progressive Rollouts →The Patch Management Lifecycle: 6 Stages from Discovery to Verification →Check the Windows release health dashboard before promoting past ring 1, and have the rollback path written down before you need it. Kernel, networking and authentication fixes are the ones that historically break things.
12 Patch Management Best Practices for 2026 →16 Chromium fixes for Edge shipped alongside this release on their own updater, and Adobe, SAP and Oracle release in the same week. OS-only patching leaves most of your real attack surface untouched.
What is Third-Party Patch Management and Why OS Patching Isn't Enough →Confirm the patch is actually present on each endpoint rather than trusting that "deployment succeeded". Keep the resulting report - it is the artefact auditors ask for, and reconstructing it later is far more work than capturing it now.
Patch Management: The Complete Guide →Trinetri does steps two through five automatically - detecting the 20 KB articles across every endpoint, staging them in rings, verifying installed state and producing the compliance evidence. See patch management →
Every month Microsoft has published back to January 2016, each with the same breakdown and the full CVE list.
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Patch Tuesday falls on the second Tuesday of every month, with updates going live at 10:00 a.m. Pacific Time. Microsoft introduced the practice in October 2003, following the Blaster worm, to cut distribution costs and give administrators a predictable cadence instead of patches arriving at random. The 10:00 a.m. timing is deliberate: it leaves a full working week to remediate before the weekend. Internally Microsoft calls it the "B" release; optional "C" and "D" preview releases follow later in the month. The next Patch Tuesday is November 10, 2026.
Microsoft fixed 35 vulnerabilities in December 2023, across Windows, Azure, Microsoft Dynamics and Microsoft Office. 4 are rated Critical, 1 were publicly disclosed before the patch shipped, and 0 were already being exploited. Note that Microsoft's release document lists 116 entries in total, but 65 of those are Azure Linux package updates and 16 are republished Chromium fixes for Edge, which is why other sources sometimes quote a much larger number.
Exploit Wednesday is the day after Patch Tuesday. Attackers compare the newly released patches against the previous version to locate the flaw each one fixes, then build working exploits from that difference - often within 24 to 48 hours. It is the reason the deployment window matters as much as the patch itself: every hour a Critical remote code execution fix sits undeployed is an hour of measurable exposure.
A workable target for most organisations: actively exploited vulnerabilities within 24 hours, publicly disclosed ones within 72 hours, remaining Critical fixes within seven days, and everything else within the month. CISA's Known Exploited Vulnerabilities catalogue sets binding deadlines for US federal agencies and is a reasonable benchmark for everyone else. Stage the rollout in rings rather than deploying everywhere at once, so a regression is caught on a pilot group instead of in production.
An out-of-band update is a patch released outside the monthly cycle because the risk will not wait for the next Patch Tuesday. Microsoft issues them for actively exploited flaws with no mitigation - most famously during the WannaCry outbreak in 2017, when it took the unusual step of patching versions of Windows that were already out of support.
Yes. Adobe aligned its releases with Patch Tuesday in November 2012, and both SAP's Security Patch Day and Oracle's quarterly Critical Patch Updates are coordinated to the same week. Part of the reason is defensive: staggered releases let attackers reverse-engineer one vendor's patch to find the same underlying flaw in another's still-unpatched product. For IT teams it means the second Tuesday is rarely just a Microsoft problem.
Edge is built on Chromium, so most of its security fixes originate with the Chromium project and are republished by Microsoft under their own CVE identifiers. They ship on Chromium's cadence rather than the Patch Tuesday cycle, and they are delivered by Edge's own updater rather than Windows Update. Counting the 16 Edge entries alongside Microsoft product fixes would inflate the headline number and imply work for your Windows Update rings that does not exist.