CVE-2026-21265
Jan. 14, 2026, 8:23 p.m.
6.4
Medium
Description
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.
Product(s) Impacted
| Vendor | Product | Versions |
|---|---|---|
| Microsoft |
|
|
Weaknesses
Common security weaknesses mapped to this vulnerability.
CWE-1329
Reliance on Component That is Not Updateable
The product contains a component that cannot be updated or patched in order to remove vulnerabilities or significant bugs.
*CPE(s)
Affected systems and software identified for this CVE.
| Type | Vendor | Product | Version | Update | Edition | Language | Software Edition | Target Software | Target Hardware | Other Information |
|---|---|---|---|---|---|---|---|---|---|---|
| o | microsoft | windows_10_1607 | / | / | / | / | / | / | x64 | / |
| o | microsoft | windows_10_1607 | / | / | / | / | / | / | x86 | / |
| o | microsoft | windows_10_1809 | / | / | / | / | / | / | x64 | / |
| o | microsoft | windows_10_1809 | / | / | / | / | / | / | x86 | / |
| o | microsoft | windows_10_21h2 | / | / | / | / | / | / | arm64 | / |
| o | microsoft | windows_10_21h2 | / | / | / | / | / | / | x64 | / |
| o | microsoft | windows_10_21h2 | / | / | / | / | / | / | x86 | / |
| o | microsoft | windows_10_22h2 | / | / | / | / | / | / | arm64 | / |
| o | microsoft | windows_10_22h2 | / | / | / | / | / | / | x64 | / |
| o | microsoft | windows_10_22h2 | / | / | / | / | / | / | x86 | / |
| o | microsoft | windows_11_23h2 | / | / | / | / | / | / | arm64 | / |
| o | microsoft | windows_11_23h2 | / | / | / | / | / | / | x64 | / |
| o | microsoft | windows_11_24h2 | / | / | / | / | / | / | arm64 | / |
| o | microsoft | windows_11_24h2 | / | / | / | / | / | / | x64 | / |
| o | microsoft | windows_11_25h2 | / | / | / | / | / | / | arm64 | / |
| o | microsoft | windows_11_25h2 | / | / | / | / | / | / | x64 | / |
| o | microsoft | windows_server_2012 | - | / | / | / | / | / | / | / |
| o | microsoft | windows_server_2012 | r2 | / | / | / | / | / | / | / |
| o | microsoft | windows_server_2016 | / | / | / | / | / | / | / | / |
| o | microsoft | windows_server_2019 | / | / | / | / | / | / | / | / |
| o | microsoft | windows_server_2022 | / | / | / | / | / | / | / | / |
| o | microsoft | windows_server_2022_23h2 | / | / | / | / | / | / | / | / |
| o | microsoft | windows_server_2025 | / | / | / | / | / | / | / | / |
Tags
CVSS Score
CVSS Data - 3.1
- Attack Vector: LOCAL
- Attack Complexity: HIGH
- Privileges Required: HIGH
- Scope: UNCHANGED
- Confidentiality Impact: HIGH
- Integrity Impact: HIGH
- Availability Impact: HIGH
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Timeline
Published: Jan. 13, 2026, 6:16 p.m.
Last Modified: Jan. 14, 2026, 8:23 p.m.
Last Modified: Jan. 14, 2026, 8:23 p.m.
Status : Analyzed
CVE has been recently published to the CVE List and has been received by the NVD.
More infoSource
*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.