# CVE-2026-80782: HID: magicmouse: do not keep a stale msc->input if no input is claimed

> A use-after-free in the Linux kernel magicmouse driver allows local attackers to execute code or crash the system by triggering a specific input device registration failure.

- **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:** 4 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-99600, BELL-CVE-2026-80782, DEBIAN-CVE-2026-80782, GHSA-43vj-4w6q-2r6j, UBUNTU-CVE-2026-80782

## What is CVE-2026-80782?

CVE-2026-80782 is an use after free vulnerability in Linux, published on 4 Sep 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:

HID: magicmouse: do not keep a stale msc->input if no input is claimed

magicmouse_input_mapping() caches the first hid_input's input_dev in
msc->input while the report descriptor is parsed, and the rest of the
driver treats a non-NULL msc->input as proof that an input device was
registered.

That does not hold on the hid-input error path. If hidinput_connect()
fails -- for instance because input_register_device() returns an error --
it unwinds through hidinput_disconnect(), which frees every input_dev it
created, including the one cached in msc->input.

The failure does not abort the probe. hid_connect() only skips the claim:

	if ((connect_mask & HID_CONNECT_HIDINPUT) && !hidinput_connect(hdev,
				connect_mask & HID_CONNECT_HIDINPUT_FORCE))
		hdev->claimed |= HID_CLAIMED_INPUT;

and the "device has no listeners" bailout below it does not fire for this
driver, which sets ->raw_event; on the USB Magic Mouse 2 / Magic Trackpad
2 paths hidraw and hiddev are claimed as well. hid_hw_start() therefore
returns 0 and magicmouse_probe() continues with msc->input pointing at
freed memory. Being non-NULL, it passes the "input not registered" check
in probe and the NULL checks in ->raw_event and ->event, so the next
input report dereferences freed memory.

Clear msc->input when the HID core did not claim an input device, so the
existing NULL checks cover this case as well.

## Which versions are affected by CVE-2026-80782?


## How do I fix CVE-2026-80782?

Apply the vendor's patch.

## Is CVE-2026-80782 being exploited?

There is no known exploitation of CVE-2026-80782 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80782 and fix it if it is affected.

What it is: CVE-2026-80782 is an use after free vulnerability in Linux, published on 4 Sep 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-2026-80782 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-2026-80782/ (Markdown: https://insights.sbomify.com/CVE-2026-80782/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80782
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80782
- OSV: https://osv.dev/vulnerability/CVE-2026-80782

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80782/
Summaries are generated and may contain mistakes; the official description above is the record.