# CVE-2026-90891: ASRock｜ASRock Polychrome SYNC/RGB software utility - Improper Access Control

> Local attackers can trigger a system reboot by sending crafted IOCTL requests to the ASRock Polychrome SYNC/RGB driver due to improper access control.

- **Severity:** Medium 6.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **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:** No
- **Published:** 14 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** GHSA-g9vq-5jvw-3c63

## What is CVE-2026-90891?

CVE-2026-90891 is a medium-severity missing authorization vulnerability in ASRock Polychrome SYNC/RGB for MB, published on 14 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

ASRock Polychrome SYNC/RGB software utility developed by ASRock Inc. has an Improper Access Control vulnerability. Authenticated local attackers can send a specially crafted IOCTL request to cause the driver to write to improperly restricted I/O ports, resulting in a forced operating system reboot.

Weakness: CWE-1256 (Improper Restriction of Software Interfaces to Hardware Features)

## Which versions are affected by CVE-2026-90891?


## How do I fix CVE-2026-90891?

No fix has been published for CVE-2026-90891 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-90891 being exploited?

There is no known exploitation of CVE-2026-90891 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90891 and fix it if it is affected.

What it is: CVE-2026-90891 is a medium-severity missing authorization vulnerability in ASRock Polychrome SYNC/RGB for MB, published on 14 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-2026-90891 in the wild and no public exploit code.

Affected product: ASRock Polychrome SYNC/RGB for MB. 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-2026-90891/ (Markdown: https://insights.sbomify.com/CVE-2026-90891/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90891
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90891
- OSV: https://osv.dev/vulnerability/CVE-2026-90891

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-90891/
Summaries are generated and may contain mistakes; the official description above is the record.