# CVE-2026-43201: APEI/GHES: ARM processor Error: don't go past allocated memory

> A missing bounds check in the Linux kernel's APEI/GHES ARM error handling allows a local attacker to cause a system crash via a malformed BIOS error record.

- **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:** 6 May 2026
- **Updated:** 23 May 2026
- **Also known as:** AZL-85886, BELL-CVE-2026-43201, DEBIAN-CVE-2026-43201, GHSA-2439-4xrr-7j2r, ROOT-OS-DEBIAN-11-CVE-2026-43201, ROOT-OS-DEBIAN-12-CVE-2026-43201, ROOT-OS-UBUNTU-2204-CVE-2026-43201, ROOT-OS-UBUNTU-2404-CVE-2026-43201, UBUNTU-CVE-2026-43201

## What is CVE-2026-43201?

CVE-2026-43201 is a medium-severity vulnerability in Linux kernel, published on 6 May 2026. 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:

APEI/GHES: ARM processor Error: don't go past allocated memory

If the BIOS generates a very small ARM Processor Error, or
an incomplete one, the current logic will fail to deferrence

	err->section_length
and
	ctx_info->size

Add checks to avoid that. With such changes, such GHESv2
records won't cause OOPSes like this:

[    1.492129] Internal error: Oops: 0000000096000005 [#1]  SMP
[    1.495449] Modules linked in:
[    1.495820] CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.18.0-rc1-00017-gabadcc3553dd-dirty #18 PREEMPT
[    1.496125] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 02/02/2022
[    1.496433] Workqueue: kacpi_notify acpi_os_execute_deferred
[    1.496967] pstate: 814000c5 (Nzcv daIF +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
[    1.497199] pc : log_arm_hw_error+0x5c/0x200
[    1.497380] lr : ghes_handle_arm_hw_error+0x94/0x220

0xffff8000811c5324 is in log_arm_hw_error (../drivers/ras/ras.c:75).
70		err_info = (struct cper_arm_err_info *)(err + 1);
71		ctx_info = (struct cper_arm_ctx_info *)(err_info + err->err_info_num);
72		ctx_err = (u8 *)ctx_info;
73
74		for (n = 0; n < err->context_info_num; n++) {
75			sz = sizeof(struct cper_arm_ctx_info) + ctx_info->size;
76			ctx_info = (struct cper_arm_ctx_info *)((long)ctx_info + sz);
77			ctx_len += sz;
78		}
79

and similar ones while trying to access section_length on an
error dump with too small size.

[ rjw: Subject tweaks ]

## Which versions are affected by CVE-2026-43201?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-43201?

Apply the vendor's patch.

## Is CVE-2026-43201 being exploited?

There is no known exploitation of CVE-2026-43201 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-2026-43201 and fix it if it is affected.

What it is: CVE-2026-43201 is a medium-severity vulnerability in Linux kernel, published on 6 May 2026. 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-2026-43201 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-2026-43201/ (Markdown: https://insights.sbomify.com/CVE-2026-43201/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43201
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43201
- OSV: https://osv.dev/vulnerability/CVE-2026-43201

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43201/
Summaries are generated and may contain mistakes; the official description above is the record.