# CVE-2026-93828: exfat: fix handling of damaged volume in exfat_create_upcase_table()

> An integer overflow in the Linux kernel exFAT driver causes an infinite loop when processing a damaged volume with a zero-sized upcase table.

- **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:** 24 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-103604, BELL-CVE-2026-93828, DEBIAN-CVE-2026-93828, GHSA-crx7-9vj2-jqgc, UBUNTU-CVE-2026-93828

## What is CVE-2026-93828?

CVE-2026-93828 is a vulnerability in Linux, published on 24 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:

exfat: fix handling of damaged volume in exfat_create_upcase_table()

When the size of the upcase table is set to zero in the dentry for any
reason(e.g. corrupted media or misbehaving device), an integer overflow
causes the module to loop indefinitely.

If the size of the upcase table is read zero, do not attempt to load the
table. Instead, fallback to loading the default upcase table. If the
size of the upcase table is zero or no upcase table is found, raise
exfat_fs_error() to mark the volume read-only.

## Which versions are affected by CVE-2026-93828?


## How do I fix CVE-2026-93828?

Apply the vendor's patch.

## Is CVE-2026-93828 being exploited?

There is no known exploitation of CVE-2026-93828 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93828 and fix it if it is affected.

What it is: CVE-2026-93828 is a vulnerability in Linux, published on 24 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-2026-93828 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-2026-93828/ (Markdown: https://insights.sbomify.com/CVE-2026-93828/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93828
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93828
- OSV: https://osv.dev/vulnerability/CVE-2026-93828

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93828/
Summaries are generated and may contain mistakes; the official description above is the record.