# CVE-2026-0421: Security feature bypass in ThinkPad L13 Gen 6 2 in 1 BIOS

> Attackers can bypass Secure Boot protection on specific Lenovo ThinkPad models when configured in User Mode, potentially allowing unauthorized code execution.

- **Severity:** High 7.0 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 14 Jan 2026
- **Updated:** 26 Feb 2026
- **Also known as:** GHSA-5m9v-m547-62qf

## What is CVE-2026-0421?

CVE-2026-0421 is a high-severity vulnerability in Lenovo ThinkPad L13 Gen 6 2 in 1 BIOS, published on 14 Jan 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

A potential vulnerability was reported in the BIOS of L13 Gen 6, L13 Gen 6 2-in-1, L14 Gen 6, and L16 Gen 2 ThinkPads which could result in Secure Boot being disabled even when configured as “On” in the BIOS setup menu. This issue only affects systems where Secure Boot is set to User Mode.

Weakness: CWE-252 (Unchecked Return Value)

## Which versions are affected by CVE-2026-0421?


## How do I fix CVE-2026-0421?

No fix has been published for CVE-2026-0421 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-0421 being exploited?

There is no known exploitation of CVE-2026-0421 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-0421 and fix it if it is affected.

What it is: CVE-2026-0421 is a high-severity vulnerability in Lenovo ThinkPad L13 Gen 6 2 in 1 BIOS, published on 14 Jan 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-0421 in the wild and no public exploit code.

Affected product: Lenovo ThinkPad L13 Gen 6 2 in 1 BIOS. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-0421/ (Markdown: https://insights.sbomify.com/CVE-2026-0421/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-0421
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-0421
- OSV: https://osv.dev/vulnerability/CVE-2026-0421

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-0421/
Summaries are generated and may contain mistakes; the official description above is the record.