# CVE-2026-89588: ACPI: APEI: GHES: fix ARM section length accounting after header

> A kernel bug in ACPI APEI GHES handling allows out-of-bounds reads, potentially leading to system crashes or code execution.

- **Severity:** High 8.4 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-89588, DEBIAN-CVE-2026-89588, GHSA-rcxp-8r6g-r5jm, UBUNTU-CVE-2026-89588

## What is CVE-2026-89588?

CVE-2026-89588 is a high-severity memory corruption vulnerability in Linux, published on 11 Sep 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:

ACPI: APEI: GHES: fix ARM section length accounting after header

In ghes_handle_arm_hw_error(), after skipping the cper_sec_proc_arm
header with (err + 1), the remaining length was reduced by sizeof(err)
(pointer size) instead of sizeof(*err) (structure size).

That overestimates the bytes left for cper_arm_err_info records and can
let the parser read past the CPER section when err_info_num is large
enough relative to error_data_length.

Use sizeof(*err) so the length accounting matches the pointer advance
and the earlier sizeof(*err) size check.

## Which versions are affected by CVE-2026-89588?


## How do I fix CVE-2026-89588?

Apply the vendor's patch.

## Is CVE-2026-89588 being exploited?

There is no known exploitation of CVE-2026-89588 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89588 and fix it if it is affected.

What it is: CVE-2026-89588 is a high-severity memory corruption vulnerability in Linux, published on 11 Sep 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-2026-89588 in the wild and no public exploit code.

Affected product: Linux. 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-2026-89588/ (Markdown: https://insights.sbomify.com/CVE-2026-89588/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89588
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89588
- OSV: https://osv.dev/vulnerability/CVE-2026-89588

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89588/
Summaries are generated and may contain mistakes; the official description above is the record.