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.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
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.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-98545 being exploited?
There is no known exploitation of CVE-2026-98545 in the wild and no public exploit code.
Sources
Also known as AZL-108849, BELL-CVE-2026-98545, DEBIAN-CVE-2026-98545, GHSA-gq8r-6748-x6m5, UBUNTU-CVE-2026-98545.