# CVE-2026-90025: usb: typec: ucsi: displayport: Fix OOB altmode array index

> A malicious USB device can trigger an out-of-bounds array access in the Linux kernel UCSI displayport driver, causing a system crash.

- **Severity:** High 7.7 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-101592, BELL-CVE-2026-90025, DEBIAN-CVE-2026-90025, GHSA-hg73-43cm-xh29, UBUNTU-CVE-2026-90025

## What is CVE-2026-90025?

CVE-2026-90025 is a high-severity memory corruption vulnerability in Linux, published on 16 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:

usb: typec: ucsi: displayport: Fix OOB altmode array index

The UCSI displayport driver indexes the connector's port altmode array
with the GET_CURRENT_CAM response after checking it is not 0xff. The
port altmode array is UCSI_MAX_ALTMODES elements long. If the PPM
returns an invalid GET_CURRENT_CAM response above UCSI_MAX_ALTMODES and
not equal to 0xff, the kernel may crash with an array index OOB error.

Update the UCSI displayport driver to verify the current cam is less
than UCSI_MAX_ALTMODES before accessing the port altmode array.

## Which versions are affected by CVE-2026-90025?


## How do I fix CVE-2026-90025?

Apply the vendor's patch.

## Is CVE-2026-90025 being exploited?

There is no known exploitation of CVE-2026-90025 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90025 and fix it if it is affected.

What it is: CVE-2026-90025 is a high-severity memory corruption vulnerability in Linux, published on 16 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-2026-90025 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-2026-90025/ (Markdown: https://insights.sbomify.com/CVE-2026-90025/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90025
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90025
- OSV: https://osv.dev/vulnerability/CVE-2026-90025

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90025/
Summaries are generated and may contain mistakes; the official description above is the record.