CVE-2026-21265
Publication date 19 January 2026
Last updated 19 January 2026
Ubuntu priority
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| secureboot-db | 25.10 questing |
Not affected
|
| 24.04 LTS noble |
Not affected
|
|
| 22.04 LTS jammy |
Not affected
|
|
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial | Ignored install media keys will never be revoked | |
| 14.04 LTS trusty | Ignored install media keys will never be revoked | |
| shim-signed | 25.10 questing |
Not affected
|
| 24.04 LTS noble |
Not affected
|
|
| 22.04 LTS jammy |
Not affected
|
|
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial | Ignored install media keys will never be revoked | |
| 14.04 LTS trusty | Ignored install media keys will never be revoked | |
| shim | 25.10 questing |
Not affected
|
| 24.04 LTS noble |
Not affected
|
|
| 22.04 LTS jammy |
Not affected
|
|
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial | Ignored install media keys will never be revoked | |
| 14.04 LTS trusty | Ignored install media keys will never be revoked |
Notes
rodrigo-zaiden
secure booting is not affect with shim versions signed with 2011 keys. that is, systems with current shim versions will still boot after the expiration date.
eslerm
secureboot-db should only ever be updated after shim secureboot-db is not updated on ESM releases as doing so would revoke install media keys Note that key revocation is required to protect against evil housekeeper attacks (such as BlackLotus)
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score |
6.4 · Medium
|
| Attack vector | Local |
| Attack complexity | High |
| Privileges required | High |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | High |
| Availability impact | High |
| Vector | CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H |