# CVE-2026-74683: Input: evdev - sanitize event type index when fetching event masks

> A local attacker can exploit speculative execution flaws in the Linux kernel evdev driver to read sensitive memory contents via out-of-bounds loads.

- **Severity:** Not scored
- **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:** 22 Aug 2026
- **Updated:** 25 Aug 2026
- **Also known as:** AZL-97269, BELL-CVE-2026-74683, DEBIAN-CVE-2026-74683, GHSA-76mx-gxxj-5f36, UBUNTU-CVE-2026-74683

## What is CVE-2026-74683?

CVE-2026-74683 is a vulnerability in Linux, published on 22 Aug 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:

Input: evdev - sanitize event type index when fetching event masks

The user-supplied event type index passed to EVIOCGMASK / EVIOCSMASK
ioctls is used to index the static counts array in evdev_get_mask_cnt()
and client evmasks array in evdev_get_mask().

While the event type is architecturally bounded by EV_CNT, speculative
execution may mispredict bounds checks and perform out-of-bounds loads.

Sanitize the event type index in evdev_get_mask_cnt() branchlessly using
array_index_mask_nospec(). This clamps the index to 0 for safe array
access and forces the returned count to 0 speculatively when the index
is out of bounds.

We do not need additional array_index_nospec() calls in evdev_get_mask()
because evdev_get_mask_cnt() speculatively forces the count (and
resulting xfer_size) to 0 for out-of-bounds types, preventing any
speculative memory access to client evmasks array.

## Which versions are affected by CVE-2026-74683?


## How do I fix CVE-2026-74683?

Apply the vendor's patch.

## Is CVE-2026-74683 being exploited?

There is no known exploitation of CVE-2026-74683 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74683 and fix it if it is affected.

What it is: CVE-2026-74683 is a vulnerability in Linux, published on 22 Aug 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-2026-74683 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-2026-74683/ (Markdown: https://insights.sbomify.com/CVE-2026-74683/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74683
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74683
- OSV: https://osv.dev/vulnerability/CVE-2026-74683

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74683/
Summaries are generated and may contain mistakes; the official description above is the record.