# CVE-2026-98593: s390/debug: Fix NULL pointer dereference in debug_info_copy()

> A local attacker can cause a denial of service in the Linux kernel s390 debug subsystem by triggering a NULL pointer dereference.

- **Severity:** Not scored
- **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:** 18 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-109208, BELL-CVE-2026-98593, DEBIAN-CVE-2026-98593, GHSA-v4qr-c46c-6qg3, UBUNTU-CVE-2026-98593

## What is CVE-2026-98593?

CVE-2026-98593 is a vulnerability in Linux, published on 18 Oct 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:

s390/debug: Fix NULL pointer dereference in debug_info_copy()

When debug_register_static() fails, it clears areas, active_pages and
active_entries but leaves the area bounds unchanged. Copying such an
area, either by opening its view file or via debug_dump(), makes
debug_info_copy() dereference the NULL pointers.

Skip the copy loop when the source has no areas.

## Which versions are affected by CVE-2026-98593?


## How do I fix CVE-2026-98593?

Apply the vendor's patch.

## Is CVE-2026-98593 being exploited?

There is no known exploitation of CVE-2026-98593 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98593 and fix it if it is affected.

What it is: CVE-2026-98593 is a vulnerability in Linux, published on 18 Oct 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-2026-98593 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-2026-98593/ (Markdown: https://insights.sbomify.com/CVE-2026-98593/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98593
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98593
- OSV: https://osv.dev/vulnerability/CVE-2026-98593

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98593/
Summaries are generated and may contain mistakes; the official description above is the record.