# CVE-2026-98769: usb: gadget: f_uac1_legacy: validate bRequest index in generic_{set,get}_cmd

> A malicious USB host can trigger out-of-bounds memory access in the Linux kernel USB audio gadget driver, potentially leading to code execution or privilege escalation.

- **Severity:** Not scored
- **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:** Yes
- **Published:** 18 Oct 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-108996, BELL-CVE-2026-98769, DEBIAN-CVE-2026-98769, GHSA-m6wv-vgq8-7pqj, UBUNTU-CVE-2026-98769

## What is CVE-2026-98769?

CVE-2026-98769 is a memory corruption vulnerability in Linux, published on 18 Oct 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

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

usb: gadget: f_uac1_legacy: validate bRequest index in generic_{set,get}_cmd

generic_set_cmd() and generic_get_cmd() use the low nibble of
ctrl->bRequest as an index into con->data[]:

    u8 cmd = (ctrl->bRequest & 0x0F);  /* 0 .. 15 */
    ...
    con->data[cmd] = value;            /* OOB when cmd >= 5 */

struct usb_audio_control (include/linux/usb/audio.h) declares data as
a 5-element array, so indices 5 through 15 write (or read) up to 44
bytes past the end of the array on the heap.

A malicious USB host can craft a class-specific SET_CUR / GET_CUR
request with an arbitrary bRequest value, triggering the out-of-bounds
access from an IRQ completion handler with no further preconditions.

Add an ARRAY_SIZE() guard to both functions.

## Which versions are affected by CVE-2026-98769?


## How do I fix CVE-2026-98769?

Apply the vendor's patch.

## Is CVE-2026-98769 being exploited?

There is no known exploitation of CVE-2026-98769 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98769 and fix it if it is affected.

What it is: CVE-2026-98769 is a memory corruption vulnerability in Linux, published on 18 Oct 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-2026-98769 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-2026-98769/ (Markdown: https://insights.sbomify.com/CVE-2026-98769/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98769
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98769
- OSV: https://osv.dev/vulnerability/CVE-2026-98769

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98769/
Summaries are generated and may contain mistakes; the official description above is the record.