CVE-2026-0421

Secure Boot disablement via unchecked return value

Published Jan 14, 2026 · Updated Jan 14, 2026

Secure Boot state handling in affected Lenovo ThinkPad BIOS allows local users with privileged BIOS access to disable boot verification. Lenovo identifies an unchecked return value but has not published the affected routine or the operation whose result is ignored. The flaw is reachable only in User Mode when BIOS and operating-system status disagree, so the system can start code that Secure Boot would reject.

CVSS severity7.0
High
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Secure Boot state handling in affected Lenovo ThinkPad BIOS allows local users with privileged BIOS access to disable boot verification. Lenovo identifies an unchecked return value but has not published the affected routine or the operation whose result is ignored. The flaw is reachable only in User Mode when BIOS and operating-system status disagree, so the system can start code that Secure Boot would reject.

The record

CVE
CVE-2026-0421
Published
Jan 14, 2026
Updated
Jan 14, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-252, T1562
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jan 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.0Lenovo Group Ltd.CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
6.5Lenovo Group Ltd.CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-252Unchecked Return Value
T1562Impair Defenses

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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