CVE-2026-80551 s390/vfio_ccw: Ensure first IDAW remains constant
A race condition in the s390 vfio_ccw driver allows attackers to manipulate IDAW addresses, potentially leading to memory corruption or privilege escalation.
- 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-2026-80551?
CVE-2026-80551 is a critical vulnerability in Linux, published on 26 Aug 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:
s390/vfio_ccw: Ensure first IDAW remains constant
The first IDAW in a list does not need to be on a 2K/4K boundary like all others, and so is read separately to accurately calculate the size of the buffer needed to read the full IDAL.
Verify that the address found in the first IDAW is unchanged between reads, to ensure a consistent set of IDAWs being worked with.
Which versions are affected by CVE-2026-80551?
How do I fix CVE-2026-80551?
Apply the vendor's patch.
Is CVE-2026-80551 being exploited?
There is no known exploitation of CVE-2026-80551 in the wild and no public exploit code.
Sources
Also known as AZL-97824, BELL-CVE-2026-80551, DEBIAN-CVE-2026-80551, GHSA-p29x-7599-2m4p, UBUNTU-CVE-2026-80551.