# CVE-2026-93053: speakup: keyhelp: guard letter_offsets possible out-of-range indexing

> A local attacker with root privileges can trigger an out-of-bounds write in the Linux kernel speakup module by overriding function names via sysfs, potentially leading to code execution.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-103004, BELL-CVE-2026-93053, DEBIAN-CVE-2026-93053, GHSA-wqw9-pm7j-m5rf, UBUNTU-CVE-2026-93053

## What is CVE-2026-93053?

CVE-2026-93053 is a memory corruption vulnerability in Linux, published on 17 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:

speakup: keyhelp: guard letter_offsets possible out-of-range indexing

help_init() builds letter_offsets[] by using the first byte of each
function name as an index via `(start & 31) - 1`. If function_names are
overridden from sysfs (root) with a name starting outside [a–z], the
index underflows or exceeds the array, leading to OOB write.

Function names can be overridden with the following commands as root:

    modprobe speakup_soft
    echo "0 _bad" > /sys/accessibility/speakup/i18n/function_names
    # then press Insert+2 on /dev/tty

This fix checks the first letter in help_init(), and if it is not in the
[a–z] range the function returns an error to the caller. Eventually this
error is propagated to drivers/accessibility/speakup/main.c:2217, which
causes a bleep sound.

## Which versions are affected by CVE-2026-93053?


## How do I fix CVE-2026-93053?

Apply the vendor's patch.

## Is CVE-2026-93053 being exploited?

There is no known exploitation of CVE-2026-93053 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93053 and fix it if it is affected.

What it is: CVE-2026-93053 is a memory corruption vulnerability in Linux, published on 17 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-2026-93053 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-2026-93053/ (Markdown: https://insights.sbomify.com/CVE-2026-93053/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93053
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93053
- OSV: https://osv.dev/vulnerability/CVE-2026-93053

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93053/
Summaries are generated and may contain mistakes; the official description above is the record.