# CVE-2026-98387: s390/crypto: Fix skcipher_walk return code handling in aes_s390

> Improper return code handling in the s390 crypto module can lead to undefined behavior or memory access issues, potentially causing system instability.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Not stated
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 14 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-108137, BELL-CVE-2026-98387, DEBIAN-CVE-2026-98387, GHSA-qwcv-vwq2-whqp, UBUNTU-CVE-2026-98387

## What is CVE-2026-98387?

CVE-2026-98387 is a vulnerability in Linux, published on 14 Oct 2026. 

### Official description

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

s390/crypto: Fix skcipher_walk return code handling in aes_s390

The return codes from skcipher_walk_virt() were not properly checked
before entering the processing loops in ecb_aes_crypt() and ctr_aes_crypt().
If skcipher_walk_virt() fails, the walk structure may be in an undefined
state, and attempting to process data could lead to incorrect behavior
or accessing uninitialized memory.

Add proper return code checking to ensure correct handling of the walk
initialization and walk advance and eventually return to the caller
with that return code.

## Which versions are affected by CVE-2026-98387?


## How do I fix CVE-2026-98387?

Apply the vendor's patch.

## Is CVE-2026-98387 being exploited?

There is no known exploitation of CVE-2026-98387 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98387 and fix it if it is affected.

What it is: CVE-2026-98387 is a vulnerability in Linux, published on 14 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-98387 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-2026-98387/ (Markdown: https://insights.sbomify.com/CVE-2026-98387/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98387
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98387
- OSV: https://osv.dev/vulnerability/CVE-2026-98387

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98387/
Summaries are generated and may contain mistakes; the official description above is the record.