# CVE-2026-97631: Pre-boot RCE in EDK II PXE driver


- **Severity:** Critical 9.5 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 22 Oct 2026
- **Updated:** 28 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-97631, UBUNTU-CVE-2026-97631

## What is CVE-2026-97631?

CVE-2026-97631 is a critical vulnerability in TianoCore EDK2, published on 22 Oct 2026. 

### Official description

EDK2 contains a vulnerability in BIOS where a user may cause “Out-of-bounds
Write”, Classic
Buffer Overflow, and “Incorrect Calculation of Buffer Size” by remote access. Successful exploitation of this vulnerability
can lead to arbitrary
code execution. It could also impact
Confidentiality,
Integrity,
and Availability.

Weakness: CWE-787 (Out-of-bounds Write), CWE-131 (Incorrect Calculation of Buffer Size), CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2026-97631?


## How do I fix CVE-2026-97631?

No fix has been published for CVE-2026-97631 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-97631 being exploited?

There is no known exploitation of CVE-2026-97631 in the wild and no public exploit code.

Public exploit code:

- https://github.com/slabbdev/uefi-pxe-cve-2026-97631 (github_poc): https://github.com/slabbdev/uefi-pxe-cve-2026-97631
- An educational laboratory for studying a PXE network-boot vulnerability in EDK II / OVMF. It builds a pinned EDK II revision, boots a UEFI virtual machine in QEMU, and includes Python proof-of-concept scripts for investigating denial of service (DoS) and memory corruption. (github_poc): https://github.com/Try2Take/CVE-2026-97631-PoC
- CVE-2026-97631 C  (github_poc): https://github.com/RayanZiani/Bootjack

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97631 and fix it if it is affected.

What it is: CVE-2026-97631 is a critical vulnerability in TianoCore EDK2, published on 22 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-97631 in the wild and no public exploit code.

Affected product: TianoCore EDK2. 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-2026-97631/ (Markdown: https://insights.sbomify.com/CVE-2026-97631/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97631
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97631
- OSV: https://osv.dev/vulnerability/CVE-2026-97631

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97631/
Summaries are generated and may contain mistakes; the official description above is the record.