GHSA-XQXC-72VF-V8F5
Vulnerability from github – Published: 2026-01-13 18:31 – Updated: 2026-01-13 18:31Windows 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.
{
"affected": [],
"aliases": [
"CVE-2026-21265"
],
"database_specific": {
"cwe_ids": [
"CWE-1329"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-01-13T18:16:25Z",
"severity": "MODERATE"
},
"details": "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.",
"id": "GHSA-xqxc-72vf-v8f5",
"modified": "2026-01-13T18:31:11Z",
"published": "2026-01-13T18:31:11Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-21265"
},
{
"type": "WEB",
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21265"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.