# CVE-2026-98232: scsi: core: Validate MODE SENSE lengths in scsi_cdl_enable()

> A malicious USB storage device can trigger an out-of-bounds read in the Linux kernel SCSI subsystem, potentially disclosing stack memory or executing code during automatic device enumeration.

- **Severity:** Not scored
- **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:** 6 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-105981, BELL-CVE-2026-98232, DEBIAN-CVE-2026-98232, GHSA-32q6-xj2g-42pm, UBUNTU-CVE-2026-98232

## What is CVE-2026-98232?

CVE-2026-98232 is a memory corruption vulnerability in Linux, published on 6 Oct 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:

scsi: core: Validate MODE SENSE lengths in scsi_cdl_enable()

scsi_cdl_enable() uses length fields returned by MODE SENSE to locate
the ATA feature mode page in a 64-byte stack buffer. A target can report
a total length shorter than its mode header and block descriptors. The
unsigned subtraction used for the MODE SELECT length can wrap, and the
separately computed buf_data can point beyond buf.

During automatic scan, enable is false, so the read-modify-write of
buf_data[4] can clear the low two bits of a target-selected
out-of-bounds stack byte. scsi_mode_select() can then copy up to 64
bytes from outside the buffer into the outgoing MODE SELECT payload,
disclosing stack contents to the target.

This is reachable while scanning a USB storage device that identifies as
an ATA device and advertises CDL support. No filesystem mount or
userspace access to the block device is required.

On upstream commit cee9395acd80 ("Linux 7.3-rc1"), a build-specific,
one-vCPU QEMU/Raw Gadget proof using QEMU-only multi-UDC allocator
sampling executed a fixed proof command inside the guest and created a
UID-0-owned marker during automatic enumeration, with KASLR and NX
enabled.

The issue was independently found during security research at Drivesec
S.r.l.

Cap the available length to the buffer size. Validate and consume the
mode header and block descriptor lengths before using the page, and
require the five bytes needed to access the CDL field.

## Which versions are affected by CVE-2026-98232?


## How do I fix CVE-2026-98232?

Apply the vendor's patch.

## Is CVE-2026-98232 being exploited?

There is no known exploitation of CVE-2026-98232 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98232 and fix it if it is affected.

What it is: CVE-2026-98232 is a memory corruption vulnerability in Linux, published on 6 Oct 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-2026-98232 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-2026-98232/ (Markdown: https://insights.sbomify.com/CVE-2026-98232/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98232
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98232
- OSV: https://osv.dev/vulnerability/CVE-2026-98232

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98232/
Summaries are generated and may contain mistakes; the official description above is the record.