# CVE-2026-21427: Other in Stellanova APS-S301 series

> Attackers can execute arbitrary code via DLL hijacking in Pioneer audio product installers, requiring user interaction to run the installer.

- **Severity:** High 8.5 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 8 Jan 2026
- **Updated:** 22 Jan 2026
- **Also known as:** GHSA-j8fw-422f-28h7

## What is CVE-2026-21427?

CVE-2026-21427 is a high-severity vulnerability in PIONEER CORPORATION Stellanova APS-S301 series, published on 8 Jan 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

The installers for multiple products provided by PIONEER CORPORATION contain an issue with the DLL search path, which may lead to insecurely loading Dynamic Link Libraries. As a result,  arbitrary code may be executed with the privileges of the running installer.

Weakness: CWE-427 (Uncontrolled Search Path Element)

## Which versions are affected by CVE-2026-21427?


## How do I fix CVE-2026-21427?

No fix has been published for CVE-2026-21427 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-21427 being exploited?

There is no known exploitation of CVE-2026-21427 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-21427 and fix it if it is affected.

What it is: CVE-2026-21427 is a high-severity vulnerability in PIONEER CORPORATION Stellanova APS-S301 series, published on 8 Jan 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-21427 in the wild and no public exploit code.

Affected product: PIONEER CORPORATION Stellanova APS-S301 series. 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-2026-21427/ (Markdown: https://insights.sbomify.com/CVE-2026-21427/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-21427
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21427
- OSV: https://osv.dev/vulnerability/CVE-2026-21427

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-21427/
Summaries are generated and may contain mistakes; the official description above is the record.