FKIE_CVE-2026-21265

Vulnerability from fkie_nvd - Published: 2026-01-13 18:16 - Updated: 2026-01-14 20:23
Severity ?
6.4 (Medium) - CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Summary
Windows Secure Boot stores Microsoft certificates in the UEFI KEK and DB. These original certificates are approaching expiration, and devices containing affected certificate versions must update them to maintain Secure Boot functionality and avoid compromising security by losing security fixes related to Windows boot manager or Secure Boot. The operating system’s certificate update protection mechanism relies on firmware components that might contain defects, which can cause certificate trust updates to fail or behave unpredictably. This leads to potential disruption of the Secure Boot trust chain and requires careful validation and deployment to restore intended security guarantees. Certificate Authority (CA) Location Purpose Expiration Date Microsoft Corporation KEK CA 2011 KEK Signs updates to the DB and DBX 06/24/2026 Microsoft Corporation UEFI CA 2011 DB Signs 3rd party boot loaders, Option ROMs, etc. 06/27/2026 Microsoft Windows Production PCA 2011 DB Signs the Windows Boot Manager 10/19/2026 For more information see this CVE and Windows Secure Boot certificate expiration and CA updates.
References
secure@microsoft.comhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21265Vendor Advisory
Impacted products
Vendor Product Version
microsoft windows_10_1607 *
microsoft windows_10_1607 *
microsoft windows_10_1809 *
microsoft windows_10_1809 *
microsoft windows_10_21h2 *
microsoft windows_10_21h2 *
microsoft windows_10_21h2 *
microsoft windows_10_22h2 *
microsoft windows_10_22h2 *
microsoft windows_10_22h2 *
microsoft windows_11_23h2 *
microsoft windows_11_23h2 *
microsoft windows_11_24h2 *
microsoft windows_11_24h2 *
microsoft windows_11_25h2 *
microsoft windows_11_25h2 *
microsoft windows_server_2012 -
microsoft windows_server_2012 r2
microsoft windows_server_2016 *
microsoft windows_server_2019 *
microsoft windows_server_2022 *
microsoft windows_server_2022_23h2 *
microsoft windows_server_2025 *
To clipboard 

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      "value": "Windows Secure Boot stores Microsoft certificates in the UEFI KEK and DB. These original certificates are approaching expiration, and devices containing affected certificate versions must update them to maintain Secure Boot functionality and avoid compromising security by losing security fixes related to Windows boot manager or Secure Boot.\nThe operating system\u2019s certificate update protection mechanism relies on firmware components that might contain defects, which can cause certificate trust updates to fail or behave unpredictably. This leads to potential disruption of the Secure Boot trust chain and requires careful validation and deployment to restore intended security guarantees.\n\n\n\nCertificate Authority (CA)\nLocation\nPurpose\nExpiration Date\n\n\n\n\nMicrosoft Corporation KEK CA 2011\nKEK\nSigns updates to the DB and DBX\n06/24/2026\n\n\nMicrosoft Corporation UEFI CA 2011\nDB\nSigns 3rd party boot loaders, Option ROMs, etc.\n06/27/2026\n\n\nMicrosoft Windows Production PCA 2011\nDB\nSigns the Windows Boot Manager\n10/19/2026\n\n\n\nFor more information see this CVE and Windows Secure Boot certificate expiration and CA updates."
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