# CVE-2026-63916: HID: wacom: Fix OOB write in wacom_hid_set_device_mode()

> A local attacker with access to a Wacom HID device can trigger an out-of-bounds write in the Linux kernel, potentially leading to code execution or privilege escalation.

- **Severity:** High 8.8 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 19 Jul 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-63916, DEBIAN-CVE-2026-63916, GHSA-r9m8-7m9v-6473, ROOT-OS-UBUNTU-2204-CVE-2026-63916, UBUNTU-CVE-2026-63916

## What is CVE-2026-63916?

CVE-2026-63916 is a high-severity memory corruption vulnerability in Linux, published on 19 Jul 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:

HID: wacom: Fix OOB write in wacom_hid_set_device_mode()

wacom_hid_set_device_mode() currently assumes that the HID_DG_INPUTMODE
usage is always located in the first field (field[0]) of the feature report.
However, a device can specify HID_DG_INPUTMODE in a different field.

If HID_DG_INPUTMODE is in a field other than the first one and the first
field has a report_count smaller than the usage_index of HID_DG_INPUTMODE,
this leads to an out-of-bounds write to r->field[0]->value.

Fix this by storing the field index of HID_DG_INPUTMODE in 'struct
hid_data' during feature mapping.  In wacom_hid_set_device_mode(), use
this stored field index to access the correct field and add bounds
checks to ensure both the field index and the value index are within
valid ranges before writing.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-63916?


## How do I fix CVE-2026-63916?

Apply the vendor's patch.

## Is CVE-2026-63916 being exploited?

There is no known exploitation of CVE-2026-63916 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-63916 and fix it if it is affected.

What it is: CVE-2026-63916 is a high-severity memory corruption vulnerability in Linux, published on 19 Jul 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-2026-63916 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-2026-63916/ (Markdown: https://insights.sbomify.com/CVE-2026-63916/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-63916
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63916
- OSV: https://osv.dev/vulnerability/CVE-2026-63916

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-63916/
Summaries are generated and may contain mistakes; the official description above is the record.