# CVE-2026-90289: drm/amd/display: Resize MST HDCP per-connector arrays to 32

> An off-by-one error in the AMD display driver's HDCP array sizing can lead to memory corruption or crashes when handling multiple connectors.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 17 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-101918, BELL-CVE-2026-90289, DEBIAN-CVE-2026-90289, GHSA-jm7v-p326-mf66, UBUNTU-CVE-2026-90289

## What is CVE-2026-90289?

CVE-2026-90289 is a high-severity vulnerability in Linux, published on 17 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:

drm/amd/display: Resize MST HDCP per-connector arrays to 32

AMDGPU_DM_MAX_DISPLAY_INDEX is 31. It suggest a maximum number of
32 connectors. But the way it's used is like MAX_DISPLAY_COUNT.
Hence we're off by one with DRM core, which supports a max of 32
connectors.

Rename AMDGPU_DM_MAX_DISPLAY_INDEX to AMDGPU_DM_MAX_DISPLAY_COUNT
to match its actual use, and increase the size to 32 to match the
originally intended size.

## Which versions are affected by CVE-2026-90289?


## How do I fix CVE-2026-90289?

Apply the vendor's patch.

## Is CVE-2026-90289 being exploited?

There is no known exploitation of CVE-2026-90289 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90289 and fix it if it is affected.

What it is: CVE-2026-90289 is a high-severity vulnerability in Linux, published on 17 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-2026-90289 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-2026-90289/ (Markdown: https://insights.sbomify.com/CVE-2026-90289/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90289
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90289
- OSV: https://osv.dev/vulnerability/CVE-2026-90289

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90289/
Summaries are generated and may contain mistakes; the official description above is the record.