# KB5073450: January 2026 cumulative update for Windows Server 23H2

KB5073450, released January 13, 2026, fixes 79 CVEs in Windows Server 2022, 23H2 Edition (Server Core installation) (build 25398.2092). One of them is being exploited (CVE-2026-20805); 1 on CISA KEV. Patch Radar priority: Patch now. The product is no longer supported.

- Web page: https://patchblox.com/security/fix/microsoft/kb5073450
- Platform: Microsoft
- Released: Jan 13, 2026
- Priority: Patch now (Closes CVE-2026-20805, exploited (CISA KEV))
- CVEs: 79, exploited: 1, on CISA KEV: 1
- Vendor advisory: https://support.microsoft.com/help/5073450

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [Windows Server 2022, 23H2 Edition (Server Core installation)](https://patchblox.com/security/data/product/microsoft/windows-server-2022-23h2-edition-server-core-installation.md) |  | 25398.2092 |

## CVEs this fix closes

| CVE | Priority | Component | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2026-20805](https://patchblox.com/security/data/cve/CVE-2026-20805.md) | Patch now | Desktop Window Manager | 5.5 | 0.0746 | CISA KEV |
| [CVE-2026-20860](https://patchblox.com/security/data/cve/CVE-2026-20860.md) | Urgent | Windows Ancillary Function Driver for WinSock | 7.8 | 0.0828 | More likely |
| [CVE-2026-20817](https://patchblox.com/security/data/cve/CVE-2026-20817.md) | Urgent | Windows Error Reporting | 7.8 | 0.0542 | More likely |
| [CVE-2026-20840](https://patchblox.com/security/data/cve/CVE-2026-20840.md) | Urgent | Windows NTFS | 7.8 | 0.0459 | More likely |
| [CVE-2026-20871](https://patchblox.com/security/data/cve/CVE-2026-20871.md) | Urgent | Desktop Window Manager | 7.8 | 0.0414 | More likely |
| [CVE-2026-20843](https://patchblox.com/security/data/cve/CVE-2026-20843.md) | Urgent | Windows Routing and Remote Access Service (RRAS) | 7.8 | 0.0342 | More likely |
| [CVE-2026-20820](https://patchblox.com/security/data/cve/CVE-2026-20820.md) | Urgent | Windows Common Log File System Driver | 7.8 | 0.0256 | More likely |
| [CVE-2026-20816](https://patchblox.com/security/data/cve/CVE-2026-20816.md) | Urgent | Windows Installer | 7.8 | 0.0244 | More likely |
| [CVE-2026-20922](https://patchblox.com/security/data/cve/CVE-2026-20922.md) | Urgent | Windows NTFS | 7.8 | 0.0108 | More likely |
| [CVE-2026-20876](https://patchblox.com/security/data/cve/CVE-2026-20876.md) | Urgent | Windows Virtualization-Based Security (VBS) Enclave | 6.7 | 0.0051 |  |
| [CVE-2023-31096](https://patchblox.com/security/data/cve/CVE-2023-31096.md) | Urgent | Agere Windows Modem Driver | 7.8 | 0.0048 | Disclosed |
| [CVE-2026-20822](https://patchblox.com/security/data/cve/CVE-2026-20822.md) | Urgent | Microsoft Graphics Component | 7.8 | 0.0039 |  |
| [CVE-2026-20929](https://patchblox.com/security/data/cve/CVE-2026-20929.md) | High | Windows HTTP.sys | 7.5 | 0.0287 |  |
| [CVE-2026-20875](https://patchblox.com/security/data/cve/CVE-2026-20875.md) | High | Windows Local Security Authority Subsystem Service (LSASS) | 7.5 | 0.0154 |  |
| [CVE-2026-20868](https://patchblox.com/security/data/cve/CVE-2026-20868.md) | High | Windows Routing and Remote Access Service (RRAS) | 8.8 | 0.0139 |  |
| [CVE-2026-20921](https://patchblox.com/security/data/cve/CVE-2026-20921.md) | High | Windows SMB Server | 7.5 | 0.0118 |  |
| [CVE-2024-55414](https://patchblox.com/security/data/cve/CVE-2024-55414.md) | High | Windows Motorola Soft Modem Driver | 7.8 | 0.0114 |  |
| [CVE-2026-20856](https://patchblox.com/security/data/cve/CVE-2026-20856.md) | High | Windows Server Update Service | 8.1 | 0.0112 |  |
| [CVE-2026-20849](https://patchblox.com/security/data/cve/CVE-2026-20849.md) | High | Windows Kerberos | 7.5 | 0.0101 |  |
| [CVE-2026-20931](https://patchblox.com/security/data/cve/CVE-2026-20931.md) | High | Windows Telephony Service | 8.0 | 0.0085 |  |
| [CVE-2026-20919](https://patchblox.com/security/data/cve/CVE-2026-20919.md) | High | Windows SMB Server | 7.5 | 0.0080 |  |
| [CVE-2026-20926](https://patchblox.com/security/data/cve/CVE-2026-20926.md) | High | Windows SMB Server | 7.5 | 0.0080 |  |
| [CVE-2026-20848](https://patchblox.com/security/data/cve/CVE-2026-20848.md) | High | Windows SMB Server | 7.5 | 0.0075 |  |
| [CVE-2026-20934](https://patchblox.com/security/data/cve/CVE-2026-20934.md) | High | Windows SMB Server | 7.5 | 0.0075 |  |
| [CVE-2026-20837](https://patchblox.com/security/data/cve/CVE-2026-20837.md) | High | Windows Media | 7.8 | 0.0068 |  |
| [CVE-2026-20864](https://patchblox.com/security/data/cve/CVE-2026-20864.md) | High | Connected Devices Platform Service (Cdpsvc) | 7.8 | 0.0055 |  |
| [CVE-2026-0386](https://patchblox.com/security/data/cve/CVE-2026-0386.md) | High | Windows Deployment Services | 7.5 | 0.0055 |  |
| [CVE-2026-20804](https://patchblox.com/security/data/cve/CVE-2026-20804.md) | High | Windows Hello | 7.7 | 0.0050 |  |
| [CVE-2026-20852](https://patchblox.com/security/data/cve/CVE-2026-20852.md) | High | Windows Hello | 7.7 | 0.0050 |  |
| [CVE-2026-20920](https://patchblox.com/security/data/cve/CVE-2026-20920.md) | High | Windows Win32K - ICOMP | 7.8 | 0.0049 |  |
| [CVE-2026-20811](https://patchblox.com/security/data/cve/CVE-2026-20811.md) | High | Windows Win32K - ICOMP | 7.8 | 0.0049 |  |
| [CVE-2026-20832](https://patchblox.com/security/data/cve/CVE-2026-20832.md) | High | Windows Remote Procedure Call Interface Definition Language (IDL) | 7.8 | 0.0048 |  |
| [CVE-2026-20857](https://patchblox.com/security/data/cve/CVE-2026-20857.md) | High | Windows Cloud Files Mini Filter Driver | 7.8 | 0.0048 |  |
| [CVE-2026-20923](https://patchblox.com/security/data/cve/CVE-2026-20923.md) | High | Windows Management Services | 7.8 | 0.0040 |  |
| [CVE-2026-20865](https://patchblox.com/security/data/cve/CVE-2026-20865.md) | High | Windows Management Services | 7.8 | 0.0039 |  |
| [CVE-2026-20863](https://patchblox.com/security/data/cve/CVE-2026-20863.md) | High | Windows Win32K - ICOMP | 7.0 | 0.0039 |  |
| [CVE-2026-20842](https://patchblox.com/security/data/cve/CVE-2026-20842.md) | High | Windows DWM | 7.0 | 0.0039 |  |
| [CVE-2026-20809](https://patchblox.com/security/data/cve/CVE-2026-20809.md) | High | Windows Kernel Memory | 7.8 | 0.0036 |  |
| [CVE-2026-20844](https://patchblox.com/security/data/cve/CVE-2026-20844.md) | High | Windows Clipboard Server | 7.4 | 0.0032 |  |
| [CVE-2026-20877](https://patchblox.com/security/data/cve/CVE-2026-20877.md) | High | Windows Management Services | 7.8 | 0.0030 |  |
| [CVE-2026-20918](https://patchblox.com/security/data/cve/CVE-2026-20918.md) | High | Windows Management Services | 7.8 | 0.0030 |  |
| [CVE-2026-20924](https://patchblox.com/security/data/cve/CVE-2026-20924.md) | High | Windows Management Services | 7.8 | 0.0030 |  |
| [CVE-2026-20826](https://patchblox.com/security/data/cve/CVE-2026-20826.md) | High | Tablet Windows User Interface (TWINUI) Subsystem | 7.8 | 0.0030 |  |
| [CVE-2026-20831](https://patchblox.com/security/data/cve/CVE-2026-20831.md) | High | Windows Ancillary Function Driver for WinSock | 7.8 | 0.0030 |  |
| [CVE-2026-20858](https://patchblox.com/security/data/cve/CVE-2026-20858.md) | High | Windows Management Services | 7.8 | 0.0029 |  |
| [CVE-2026-20861](https://patchblox.com/security/data/cve/CVE-2026-20861.md) | High | Windows Management Services | 7.8 | 0.0029 |  |
| [CVE-2026-20866](https://patchblox.com/security/data/cve/CVE-2026-20866.md) | High | Windows Management Services | 7.8 | 0.0029 |  |
| [CVE-2026-20867](https://patchblox.com/security/data/cve/CVE-2026-20867.md) | High | Windows Management Services | 7.8 | 0.0029 |  |
| [CVE-2026-20873](https://patchblox.com/security/data/cve/CVE-2026-20873.md) | High | Windows Management Services | 7.8 | 0.0029 |  |
| [CVE-2026-20874](https://patchblox.com/security/data/cve/CVE-2026-20874.md) | High | Windows Management Services | 7.8 | 0.0029 |  |
| [CVE-2026-20808](https://patchblox.com/security/data/cve/CVE-2026-20808.md) | High | Printer Association Object | 7.0 | 0.0029 |  |
| [CVE-2026-20814](https://patchblox.com/security/data/cve/CVE-2026-20814.md) | High | Graphics Kernel | 7.0 | 0.0029 |  |
| [CVE-2026-20869](https://patchblox.com/security/data/cve/CVE-2026-20869.md) | High | Windows Local Session Manager (LSM) | 7.0 | 0.0029 |  |
| [CVE-2026-20836](https://patchblox.com/security/data/cve/CVE-2026-20836.md) | High | Graphics Kernel | 7.0 | 0.0029 |  |
| [CVE-2026-20872](https://patchblox.com/security/data/cve/CVE-2026-20872.md) | Routine | Windows NTLM | 6.5 | 0.1979 |  |
| [CVE-2026-20925](https://patchblox.com/security/data/cve/CVE-2026-20925.md) | Routine | Windows NTLM | 6.5 | 0.1793 |  |
| [CVE-2026-20847](https://patchblox.com/security/data/cve/CVE-2026-20847.md) | Routine | Windows Shell | 6.5 | 0.0134 |  |
| [CVE-2026-20812](https://patchblox.com/security/data/cve/CVE-2026-20812.md) | Routine | Windows LDAP - Lightweight Directory Access Protocol | 6.5 | 0.0112 |  |
| [CVE-2026-21265](https://patchblox.com/security/data/cve/CVE-2026-21265.md) | Routine | Windows Secure Boot | 6.4 | 0.0110 | Disclosed |
| [CVE-2026-20927](https://patchblox.com/security/data/cve/CVE-2026-20927.md) | Routine | Windows SMB Server | 5.3 | 0.0091 |  |
| [CVE-2026-20824](https://patchblox.com/security/data/cve/CVE-2026-20824.md) | Routine | Windows Remote Assistance | 5.5 | 0.0086 |  |
| [CVE-2026-20834](https://patchblox.com/security/data/cve/CVE-2026-20834.md) | Routine | Windows Shell | 4.6 | 0.0074 |  |
| [CVE-2026-20818](https://patchblox.com/security/data/cve/CVE-2026-20818.md) | Routine | Windows Kernel | 6.2 | 0.0071 |  |
| [CVE-2026-20821](https://patchblox.com/security/data/cve/CVE-2026-20821.md) | Routine | Windows Remote Procedure Call | 6.2 | 0.0070 |  |
| [CVE-2026-20932](https://patchblox.com/security/data/cve/CVE-2026-20932.md) | Routine | Windows File Explorer | 5.5 | 0.0068 |  |
| [CVE-2026-20823](https://patchblox.com/security/data/cve/CVE-2026-20823.md) | Routine | Windows File Explorer | 5.5 | 0.0066 |  |
| [CVE-2026-20827](https://patchblox.com/security/data/cve/CVE-2026-20827.md) | Routine | Tablet Windows User Interface (TWINUI) Subsystem | 5.5 | 0.0066 |  |
| [CVE-2026-20838](https://patchblox.com/security/data/cve/CVE-2026-20838.md) | Routine | Windows Kernel | 5.5 | 0.0065 |  |
| [CVE-2026-20828](https://patchblox.com/security/data/cve/CVE-2026-20828.md) | Routine | Windows Internet Connection Sharing (ICS) | 4.6 | 0.0064 |  |
| [CVE-2026-20862](https://patchblox.com/security/data/cve/CVE-2026-20862.md) | Routine | Windows Management Services | 5.5 | 0.0064 |  |
| [CVE-2026-20829](https://patchblox.com/security/data/cve/CVE-2026-20829.md) | Routine | Windows TPM | 5.5 | 0.0056 |  |
| [CVE-2026-20835](https://patchblox.com/security/data/cve/CVE-2026-20835.md) | Routine | Capability Access Management Service (camsvc) | 5.5 | 0.0056 |  |
| [CVE-2026-20833](https://patchblox.com/security/data/cve/CVE-2026-20833.md) | Routine | Windows Kerberos | 5.5 | 0.0053 |  |
| [CVE-2026-20825](https://patchblox.com/security/data/cve/CVE-2026-20825.md) | Routine | Windows Hyper-V | 4.4 | 0.0053 |  |
| [CVE-2026-20939](https://patchblox.com/security/data/cve/CVE-2026-20939.md) | Routine | Windows File Explorer | 5.5 | 0.0051 |  |
| [CVE-2026-20937](https://patchblox.com/security/data/cve/CVE-2026-20937.md) | Routine | Windows File Explorer | 5.5 | 0.0051 |  |
| [CVE-2026-20936](https://patchblox.com/security/data/cve/CVE-2026-20936.md) | Routine | Windows NDIS | 4.3 | 0.0048 |  |
| [CVE-2026-20839](https://patchblox.com/security/data/cve/CVE-2026-20839.md) | Routine | Windows Client-Side Caching (CSC) Service | 5.5 | 0.0048 |  |
| [CVE-2026-20962](https://patchblox.com/security/data/cve/CVE-2026-20962.md) | Routine | Dynamic Root of Trust for Measurement (DRTM) | 4.4 | 0.0044 |  |

---

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