CVE-2026-98648 s390/uv: Prevent potential out-of-bounds read
An out-of-bounds read in the Linux kernel s390 UV driver allows attackers to read memory or cause a crash when handling many secrets.
- 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-2026-98648?
CVE-2026-98648 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:
s390/uv: Prevent potential out-of-bounds read
When the system has more than 85 secrets, the uv_secret_list struct array only holds up to 85 items per page, resulting in an out of bounds read in find_secret_in_page if the targeted secret is in the next page or not stored at all.
Fix this by looping over the number of stored secrets which is the per sub-list count of stored secrets and not the overall count.
Which versions are affected by CVE-2026-98648?
How do I fix CVE-2026-98648?
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-2026-98648 being exploited?
There is no known exploitation of CVE-2026-98648 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-98648, DEBIAN-CVE-2026-98648, GHSA-88ff-f8f3-f4qh, UBUNTU-CVE-2026-98648.