Microsoft January 2026 Patch Tuesday fixes 114 flaws and actively exploited flaw
Take action: Another important and urgent advisory: One zero-day vulnerability is actively exploited in the wild, two more reported and eight critical flaws in Office and WIndows. Patch your Windows Operating Systems ASAP, then Microsoft Office. Then review the advisory for the rest of the Microsoft products and Windows components you use.
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Microsoft fixed 114 security flaws in its January 2026 Patch Tuesday update. This release includes eight critical bugs and three zero-days. One zero-day is currently actively exploited.
The update fixes problems in Windows, Office, and Azure that allow attackers to run code or gain higher privileges.
Zero days and actively exploited:
- CVE-2026-20805 (CVSS score 5.5) an information disclosure vulnerability in the Desktop Window Manager. It is actively exploited to steal data from the Desktop Window Manager. This flaw lets a user read memory from a remote port. Microsoft Threat Intelligence reports the exploitation activity but did not share how the attack works. This bug shows that local users can still reach sensitive system memory.
- CVE-2026-21265 (CVSS score 6.4) Secure Boot Certificate Expiration Security Feature Bypass vulnerability affecting Windows Secure Boot certificates issued in 2011 that are nearing expiration, potentially allowing threat actors to bypass Secure Boot protections on systems that remain unpatched. If not fixed, the boot security chain will fail by mid-2026.
- CVE-2023-31096 (CVSS score 7.8) addresses vulnerabilities in third-party Agere Soft Modem drivers that ship with supported Windows versions. Previously exploited to gain administrative privileges on compromised systems, Microsoft has now completely removed the vulnerable agrsm64.sys and agrsm.sys drivers from Windows in the January 2026 cumulative update..
Critical patched flaws:
- CVE-2026-20952 (CVSS score 8.4) - Microsoft Office Remote Code Execution Vulnerability
- CVE-2026-20953 (CVSS score 8.4) - Microsoft Office Remote Code Execution Vulnerability
- CVE-2026-20944 (CVSS score 8.4) - Microsoft Word Remote Code Execution Vulnerability
- CVE-2026-20957 (CVSS score 7.8) - Microsoft Excel Remote Code Execution Vulnerability
- CVE-2026-20955 (CVSS score 7.8) - Microsoft Excel Remote Code Execution Vulnerability
- CVE-2026-20822 (CVSS score 7.8) - Windows Graphics Component Elevation of Privilege Vulnerability
- CVE-2026-20854 (CVSS score 7.5) - Windows Local Security Authority Subsystem Service (LSASS) Remote Code Execution Vulnerability
- CVE-2026-20876 (CVSS score 6.7) - Windows Virtualization-Based Security (VBS) Enclave Elevation of Privilege Vulnerability
The patch cycle includes:
- 57 Elevation of Privilege vulnerabilities
- 3 Security Feature Bypass vulnerabilities
- 22 Remote Code Execution vulnerabilities
- 22 Information Disclosure vulnerabilities
- 2 Denial of Service vulnerabilities
- 5 Spoofing vulnerabilities
Full patch list
| Tag | CVE ID | CVE Title | Severity |
|---|---|---|---|
| Agere Windows Modem Driver | CVE-2023-31096 | MITRE: CVE-2023-31096 Windows Agere Soft Modem Driver Elevation of Privilege Vulnerability | Important |
| Azure Connected Machine Agent | CVE-2026-21224 | Azure Connected Machine Agent Elevation of Privilege Vulnerability | Important |
| Azure Core shared client library for Python | CVE-2026-21226 | Azure Core shared client library for Python Remote Code Execution Vulnerability | Important |
| Capability Access Management Service (camsvc) | CVE-2026-20835 | Capability Access Management Service (camsvc) Information Disclosure Vulnerability | Important |
| Capability Access Management Service (camsvc) | CVE-2026-20851 | Capability Access Management Service (camsvc) Information Disclosure Vulnerability | Important |
| Capability Access Management Service (camsvc) | CVE-2026-20830 | Capability Access Management Service (camsvc) Elevation of Privilege Vulnerability | Important |
| Capability Access Management Service (camsvc) | CVE-2026-21221 | Capability Access Management Service (camsvc) Elevation of Privilege Vulnerability | Important |
| Capability Access Management Service (camsvc) | CVE-2026-20815 | Capability Access Management Service (camsvc) Elevation of Privilege Vulnerability | Important |
| Connected Devices Platform Service (Cdpsvc) | CVE-2026-20864 | Windows Connected Devices Platform Service Elevation of Privilege Vulnerability | Important |
| Desktop Window Manager | CVE-2026-20805 | Desktop Window Manager Information Disclosure Vulnerability | Important |
| Desktop Window Manager | CVE-2026-20871 | Desktop Windows Manager Elevation of Privilege Vulnerability | Important |
| Dynamic Root of Trust for Measurement (DRTM) | CVE-2026-20962 | Dynamic Root of Trust for Measurement (DRTM) Information Disclosure Vulnerability | Important |
| Graphics Kernel | CVE-2026-20836 | DirectX Graphics Kernel Elevation of Privilege Vulnerability | Important |
| Graphics Kernel | CVE-2026-20814 | DirectX Graphics Kernel Elevation of Privilege Vulnerability | Important |
| Host Process for Windows Tasks | CVE-2026-20941 | Host Process for Windows Tasks Elevation of Privilege Vulnerability | Important |
| Inbox COM Objects | CVE-2026-21219 | Inbox COM Objects (Global Memory) Remote Code Execution Vulnerability | Important |
| Mariner | CVE-2026-21444 | libtpms returns wrong initialization vector when certain symmetric ciphers are used | Moderate |
| Mariner | CVE-2025-68758 | backlight: led-bl: Add devlink to supplier LEDs | Moderate |
| Mariner | CVE-2025-68757 | drm/vgem-fence: Fix potential deadlock on release | Moderate |
| Mariner | CVE-2025-68764 | NFS: Automounted filesystems should inherit ro,noexec,nodev,sync flags | Moderate |
| Mariner | CVE-2025-68756 | block: Use RCU in blk_mq_[un]quiesce_tagset() instead of set->tag_list_lock | Important |
| Mariner | CVE-2025-68763 | crypto: starfive - Correctly handle return of sg_nents_for_len | Moderate |
| Mariner | CVE-2025-68755 | staging: most: remove broken i2c driver | Moderate |
| Mariner | CVE-2025-68759 | wifi: rtl818x: Fix potential memory leaks in rtl8180_init_rx_ring() | Important |
| Mariner | CVE-2025-68766 | irqchip/mchp-eic: Fix error code in mchp_eic_domain_alloc() | Important |
| Mariner | CVE-2025-68753 | ALSA: firewire-motu: add bounds check in put_user loop for DSP events | Important |
| Mariner | CVE-2025-68765 | mt76: mt7615: Fix memory leak in mt7615_mcu_wtbl_sta_add() | Moderate |
| Microsoft Edge (Chromium-based) | CVE-2026-0628 | Chromium: CVE-2026-0628 Insufficient policy enforcement in WebView tag | Unknown |
| Microsoft Graphics Component | CVE-2026-20822 | Windows Graphics Component Elevation of Privilege Vulnerability | Critical |
| Microsoft Office | CVE-2026-20952 | Microsoft Office Remote Code Execution Vulnerability | Critical |
| Microsoft Office | CVE-2026-20953 | Microsoft Office Remote Code Execution Vulnerability | Critical |
| Microsoft Office | CVE-2026-20943 | Microsoft Office Click-To-Run Elevation of Privilege Vulnerability | Important |
| Microsoft Office Excel | CVE-2026-20949 | Microsoft Excel Security Feature Bypass Vulnerability | Important |
| Microsoft Office Excel | CVE-2026-20950 | Microsoft Excel Remote Code Execution Vulnerability | Important |
| Microsoft Office Excel | CVE-2026-20956 | Microsoft Excel Remote Code Execution Vulnerability | Important |
| Microsoft Office Excel | CVE-2026-20957 | Microsoft Excel Remote Code Execution Vulnerability | Critical |
| Microsoft Office Excel | CVE-2026-20946 | Microsoft Excel Remote Code Execution Vulnerability | Important |
| Microsoft Office Excel | CVE-2026-20955 | Microsoft Excel Remote Code Execution Vulnerability | Critical |
| Microsoft Office SharePoint | CVE-2026-20958 | Microsoft SharePoint Information Disclosure Vulnerability | Important |
| Microsoft Office SharePoint | CVE-2026-20959 | Microsoft SharePoint Server Spoofing Vulnerability | Important |
| Microsoft Office SharePoint | CVE-2026-20947 | Microsoft SharePoint Server Remote Code Execution Vulnerability | Important |
| Microsoft Office SharePoint | CVE-2026-20951 | Microsoft SharePoint Server Remote Code Execution Vulnerability | Important |
| Microsoft Office SharePoint | CVE-2026-20963 | Microsoft SharePoint Remote Code Execution Vulnerability | Important |
| Microsoft Office Word | CVE-2026-20948 | Microsoft Word Remote Code Execution Vulnerability | Important |
| Microsoft Office Word | CVE-2026-20944 | Microsoft Word Remote Code Execution Vulnerability | Critical |
| Printer Association Object | CVE-2026-20808 | Windows File Explorer Elevation of Privilege Vulnerability | Important |
| SQL Server | CVE-2026-20803 | Microsoft SQL Server Elevation of Privilege Vulnerability | Important |
| Tablet Windows User Interface (TWINUI) Subsystem | CVE-2026-20827 | Tablet Windows User Interface (TWINUI) Subsystem Information Disclosure Vulnerability | Important |
| Tablet Windows User Interface (TWINUI) Subsystem | CVE-2026-20826 | Tablet Windows User Interface (TWINUI) Subsystem Information Disclosure Vulnerability | Important |
| Windows Admin Center | CVE-2026-20965 | Windows Admin Center Elevation of Privilege Vulnerability | Important |
| Windows Ancillary Function Driver for WinSock | CVE-2026-20831 | Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability | Important |
| Windows Ancillary Function Driver for WinSock | CVE-2026-20860 | Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability | Important |
| Windows Ancillary Function Driver for WinSock | CVE-2026-20810 | Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability | Important |
| Windows Client-Side Caching (CSC) Service | CVE-2026-20839 | Windows Client-Side Caching (CSC) Service Information Disclosure Vulnerability | Important |
| Windows Clipboard Server | CVE-2026-20844 | Windows Clipboard Server Elevation of Privilege Vulnerability | Important |
| Windows Cloud Files Mini Filter Driver | CVE-2026-20940 | Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability | Important |
| Windows Cloud Files Mini Filter Driver | CVE-2026-20857 | Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability | Important |
| Windows Common Log File System Driver | CVE-2026-20820 | Windows Common Log File System Driver Elevation of Privilege Vulnerability | Important |
| Windows Deployment Services | CVE-2026-0386 | Windows Deployment Services Remote Code Execution Vulnerability | Important |
| Windows DWM | CVE-2026-20842 | Microsoft DWM Core Library Elevation of Privilege Vulnerability | Important |
| Windows Error Reporting | CVE-2026-20817 | Windows Error Reporting Service Elevation of Privilege Vulnerability | Important |
| Windows File Explorer | CVE-2026-20939 | Windows File Explorer Information Disclosure Vulnerability | Important |
| Windows File Explorer | CVE-2026-20932 | Windows File Explorer Information Disclosure Vulnerability | Important |
| Windows File Explorer | CVE-2026-20937 | Windows File Explorer Information Disclosure Vulnerability | Important |
| Windows File Explorer | CVE-2026-20823 | Windows File Explorer Information Disclosure Vulnerability | Important |
| Windows Hello | CVE-2026-20852 | Windows Hello Tampering Vulnerability | Important |
| Windows Hello | CVE-2026-20804 | Windows Hello Tampering Vulnerability | Important |
| Windows HTTP.sys | CVE-2026-20929 | Windows HTTP.sys Elevation of Privilege Vulnerability | Important |
| Windows Hyper-V | CVE-2026-20825 | Windows Hyper-V Information Disclosure Vulnerability | Important |
| Windows Installer | CVE-2026-20816 | Windows Installer Elevation of Privilege Vulnerability | Important |
| Windows Internet Connection Sharing (ICS) | CVE-2026-20828 | Windows rndismp6.sys Information Disclosure Vulnerability | Important |
| Windows Kerberos | CVE-2026-20849 | Windows Kerberos Elevation of Privilege Vulnerability | Important |
| Windows Kerberos | CVE-2026-20833 | Windows Kerberos Information Disclosure Vulnerability | Important |
| Windows Kernel | CVE-2026-20838 | Windows Kernel Information Disclosure Vulnerability | Important |
| Windows Kernel | CVE-2026-20818 | Windows Kernel Information Disclosure Vulnerability | Important |
| Windows Kernel Memory | CVE-2026-20809 | Windows Kernel Memory Elevation of Privilege Vulnerability | Important |
| Windows Kernel-Mode Drivers | CVE-2026-20859 | Windows Kernel-Mode Driver Elevation of Privilege Vulnerability | Important |
| Windows LDAP - Lightweight Directory Access Protocol | CVE-2026-20812 | LDAP Tampering Vulnerability | Important |
| Windows Local Security Authority Subsystem Service (LSASS) | CVE-2026-20854 | Windows Local Security Authority Subsystem Service (LSASS) Remote Code Execution Vulnerability | Critical |
| Windows Local Security Authority Subsystem Service (LSASS) | CVE-2026-20875 | Windows Local Security Authority Subsystem Service (LSASS) Denial of Service Vulnerability | Important |
| Windows Local Session Manager (LSM) | CVE-2026-20869 | Windows Local Session Manager (LSM) Elevation of Privilege Vulnerability | Important |
| Windows Management Services | CVE-2026-20924 | Windows Management Services Elevation of Privilege Vulnerability | Important |
| Windows Management Services | CVE-2026-20874 | Windows Management Services Elevation of Privilege Vulnerability | Important |
| Windows Management Services | CVE-2026-20862 | Windows Management Services Information Disclosure Vulnerability | Important |
| Windows Management Services | CVE-2026-20866 | Windows Management Services Elevation of Privilege Vulnerability | Important |
| Windows Management Services | CVE-2026-20867 | Windows Management Services Elevation of Privilege Vulnerability | Important |
| Windows Management Services | CVE-2026-20861 | Windows Management Services Elevation of Privilege Vulnerability | Important |
| Windows Management Services | CVE-2026-20865 | Windows Management Services Elevation of Privilege Vulnerability | Important |
| Windows Management Services | CVE-2026-20858 | Windows Management Services Elevation of Privilege Vulnerability | Important |
| Windows Management Services | CVE-2026-20918 | Windows Management Services Elevation of Privilege Vulnerability | Important |
| Windows Management Services | CVE-2026-20877 | Windows Management Services Elevation of Privilege Vulnerability | Important |
| Windows Management Services | CVE-2026-20923 | Windows Management Services Elevation of Privilege Vulnerability | Important |
| Windows Management Services | CVE-2026-20873 | Windows Management Services Elevation of Privilege Vulnerability | Important |
| Windows Media | CVE-2026-20837 | Windows Media Remote Code Execution Vulnerability | Important |
| Windows Motorola Soft Modem Driver | CVE-2024-55414 | Windows Motorola Soft Modem Driver Elevation of Privilege Vulnerability | Important |
| Windows NDIS | CVE-2026-20936 | Windows NDIS Information Disclosure Vulnerability | Important |
| Windows NTFS | CVE-2026-20922 | Windows NTFS Remote Code Execution Vulnerability | Important |
| Windows NTFS | CVE-2026-20840 | Windows NTFS Remote Code Execution Vulnerability | Important |
| Windows NTLM | CVE-2026-20925 | NTLM Hash Disclosure Spoofing Vulnerability | Important |
| Windows NTLM | CVE-2026-20872 | NTLM Hash Disclosure Spoofing Vulnerability | Important |
| Windows Remote Assistance | CVE-2026-20824 | Windows Remote Assistance Security Feature Bypass Vulnerability | Important |
| Windows Remote Procedure Call | CVE-2026-20821 | Remote Procedure Call Information Disclosure Vulnerability | Important |
| Windows Remote Procedure Call Interface Definition Language (IDL) | CVE-2026-20832 | Windows Remote Procedure Call Interface Definition Language (IDL) Elevation of Privilege Vulnerability | Important |
| Windows Routing and Remote Access Service (RRAS) | CVE-2026-20868 | Windows Routing and Remote Access Service (RRAS) Remote Code Execution Vulnerability | Important |
| Windows Routing and Remote Access Service (RRAS) | CVE-2026-20843 | Windows Routing and Remote Access Service (RRAS) Elevation of Privilege Vulnerability | Important |
| Windows Secure Boot | CVE-2026-21265 | Secure Boot Certificate Expiration Security Feature Bypass Vulnerability | Important |
| Windows Server Update Service | CVE-2026-20856 | Windows Server Update Service (WSUS) Remote Code Execution Vulnerability | Important |
| Windows Shell | CVE-2026-20834 | Windows Spoofing Vulnerability | Important |
| Windows Shell | CVE-2026-20847 | Microsoft Windows File Explorer Spoofing Vulnerability | Important |
| Windows SMB Server | CVE-2026-20926 | Windows SMB Server Elevation of Privilege Vulnerability | Important |
| Windows SMB Server | CVE-2026-20921 | Windows SMB Server Elevation of Privilege Vulnerability | Important |
| Windows SMB Server | CVE-2026-20919 | Windows SMB Server Elevation of Privilege Vulnerability | Important |
| Windows SMB Server | CVE-2026-20927 | Windows SMB Server Denial of Service Vulnerability | Important |
| Windows SMB Server | CVE-2026-20848 | Windows SMB Server Elevation of Privilege Vulnerability | Important |
| Windows SMB Server | CVE-2026-20934 | Windows SMB Server Elevation of Privilege Vulnerability | Important |
| Windows Telephony Service | CVE-2026-20931 | Windows Telephony Service Elevation of Privilege Vulnerability | Important |
| Windows TPM | CVE-2026-20829 | TPM Trustlet Information Disclosure Vulnerability | Important |
| Windows Virtualization-Based Security (VBS) Enclave | CVE-2026-20938 | Windows Virtualization-Based Security (VBS) Enclave Elevation of Privilege Vulnerability | Important |
| Windows Virtualization-Based Security (VBS) Enclave | CVE-2026-20935 | Windows Virtualization-Based Security (VBS) Information Disclosure Vulnerability | Important |
| Windows Virtualization-Based Security (VBS) Enclave | CVE-2026-20819 | Windows Virtualization-Based Security (VBS) Information Disclosure Vulnerability | Important |
| Windows Virtualization-Based Security (VBS) Enclave | CVE-2026-20876 | Windows Virtualization-Based Security (VBS) Enclave Elevation of Privilege Vulnerability | Critical |
| Windows WalletService | CVE-2026-20853 | Windows WalletService Elevation of Privilege Vulnerability | Important |
| Windows Win32K - ICOMP | CVE-2026-20811 | Win32k Elevation of Privilege Vulnerability | Important |
| Windows Win32K - ICOMP | CVE-2026-20870 | Windows Win32 Kernel Subsystem Elevation of Privilege Vulnerability | Important |
| Windows Win32K - ICOMP | CVE-2026-20920 | Win32k Elevation of Privilege Vulnerability | Important |
| Windows Win32K - ICOMP | CVE-2026-20863 | Win32k Elevation of Privilege Vulnerability | Important |
