# CVE-2026-98545: ata: libata-scsi: bound the ATA passthru sense descriptor writes

> A malicious ATAPI device can trigger out-of-bounds writes in the Linux kernel via crafted sense data, potentially leading to code execution or system crash.

- **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:** 18 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-108849, BELL-CVE-2026-98545, DEBIAN-CVE-2026-98545, GHSA-gq8r-6748-x6m5, UBUNTU-CVE-2026-98545

## What is CVE-2026-98545?

CVE-2026-98545 is a memory corruption vulnerability in Linux, published on 18 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:

ata: libata-scsi: bound the ATA passthru sense descriptor writes

When an ATA PASS-THROUGH command to an ATAPI device fails, the sense
buffer holds the device's REQUEST SENSE reply, and
ata_scsi_set_passthru_sense_fields() trusts its additional length
byte, sb[7], when adding the ATA Status Return descriptor.  A faulty
or malicious device can use that to make the kernel read and write
past the 96-byte buffer in three ways:

- scsi_sense_desc_find() is passed sb[7] + 8 as the buffer length, so
  its clamp against sb[7] does nothing and the walk runs off the end.
- A type-9 descriptor found near the end is filled in unchecked.
- A new descriptor at sb[8 + len] needs len + 22 bytes, not len + 14,
  so len 75..82 writes up to 8 bytes past the end.

Reproduced with KASAN under qemu, with the emulated ATAPI REQUEST SENSE
reply patched:

  BUG: KASAN: slab-out-of-bounds in scsi_sense_desc_find+0x1a5/0x210
  BUG: KASAN: slab-out-of-bounds in ata_scsi_qc_complete+0x1a15/0x1a50

Both are gone with this patch, and a valid descriptor is still filled
in.

## Which versions are affected by CVE-2026-98545?


## How do I fix CVE-2026-98545?

Apply the vendor's patch.

## Is CVE-2026-98545 being exploited?

There is no known exploitation of CVE-2026-98545 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98545 and fix it if it is affected.

What it is: CVE-2026-98545 is a memory corruption vulnerability in Linux, published on 18 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-2026-98545 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-2026-98545/ (Markdown: https://insights.sbomify.com/CVE-2026-98545/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98545
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98545
- OSV: https://osv.dev/vulnerability/CVE-2026-98545

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98545/
Summaries are generated and may contain mistakes; the official description above is the record.