JPCERT-AT-2026-0001
                                                             JPCERT/CC
                                                            2026-01-14

                 <<< JPCERT/CC Alert 2026-01-14 >>>

         Microsoft Releases January 2026 Security Updates

       https://www.jpcert.or.jp/english/at/2026/at260001.html


I. Overview
Microsoft has released January 2026 Security Updates to address the
vulnerabilities in their products. Remote attackers leveraging these
vulnerabilities may be able to execute arbitrary code.

    Microsoft Corporation
    January 2026 Security Updates
    https://msrc.microsoft.com/update-guide/en-us/releaseNote/2026-Jan

According to Microsoft, among the vulnerabilities, the following
vulnerability has been confirmed to be exploited in the wild. Please
consider applying the security update programs by referring to
the information provided by Microsoft.

    CVE-2026-20805
    Desktop Window Manager Information Disclosure Vulnerability
    https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-20805


II. Solution
Please apply the security update programs through Microsoft Update, Windows
Update, etc.

    Microsoft Update Catalog
    https://www.catalog.update.microsoft.com/

    Windows Update: FAQ
    https://support.microsoft.com/en-us/help/12373/windows-update-faq


III. References
    Microsoft Corporation
    Release Notes
    https://msrc.microsoft.com/update-guide/

If you have any information regarding this alert, please contact
JPCERT/CC.

======================================================================
JPCERT Coordination Center (Early Warning Group)
MAIL: ew-info@jpcert.or.jp
https://www.jpcert.or.jp/english/