# CVE-2024-26678: x86/efistub: Use 1:1 file:memory mapping for PE/COFF .compat section

> A kernel image layout violation may cause rejection by strict EFI loaders, preventing boot on systems with mixed EFI support enabled.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Apr 2024
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2024-26678, DEBIAN-CVE-2024-26678, GHSA-5g26-fc68-x9f2, UBUNTU-CVE-2024-26678

## What is CVE-2024-26678?

CVE-2024-26678 is a medium-severity vulnerability in Linux kernel, published on 2 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

x86/efistub: Use 1:1 file:memory mapping for PE/COFF .compat section

The .compat section is a dummy PE section that contains the address of
the 32-bit entrypoint of the 64-bit kernel image if it is bootable from
32-bit firmware (i.e., CONFIG_EFI_MIXED=y)

This section is only 8 bytes in size and is only referenced from the
loader, and so it is placed at the end of the memory view of the image,
to avoid the need for padding it to 4k, which is required for sections
appearing in the middle of the image.

Unfortunately, this violates the PE/COFF spec, and even if most EFI
loaders will work correctly (including the Tianocore reference
implementation), PE loaders do exist that reject such images, on the
basis that both the file and memory views of the file contents should be
described by the section headers in a monotonically increasing manner
without leaving any gaps.

So reorganize the sections to avoid this issue. This results in a slight
padding overhead (< 4k) which can be avoided if desired by disabling
CONFIG_EFI_MIXED (which is only needed in rare cases these days)

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2024-26678?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-26678?

Apply the vendor's patch.

## Is CVE-2024-26678 being exploited?

There is no known exploitation of CVE-2024-26678 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-26678 and fix it if it is affected.

What it is: CVE-2024-26678 is a medium-severity vulnerability in Linux kernel, published on 2 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-26678 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2024-26678/ (Markdown: https://insights.sbomify.com/CVE-2024-26678/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-26678
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-26678
- OSV: https://osv.dev/vulnerability/CVE-2024-26678

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-26678/
Summaries are generated and may contain mistakes; the official description above is the record.