CVE-2026-98248 arm64: percpu: Fix LSE operations on {8,16}-bit types
A flaw in Linux kernel arm64 percpu LSE operations causes incorrect memory access sizes, potentially leading to memory corruption or data leakage.
- 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-2026-98248?
CVE-2026-98248 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:
arm64: percpu: Fix LSE operations on {8,16}-bit types
The assembly for __percpu_##name##_case_##sz() and __percpu_##name##_return_case_##sz() doesn't use the 'sfx' macro argument to form the LSE instruction. Without 'sfx', a W register argument will imply a 32-bit memory location, and consequently {8,16}-bit ops will erroneously read and write 32 bits of memory when the LSE instruction is used.
Fix this by appending 'sfx' to 'op_lse' to LSE instruction. It is not necessary (and not valid) to append 'sfx' to 'op_llsc', as 'op_llsc' is a register-register operation which does not access memory (and does not take a size suffix).
Which versions are affected by CVE-2026-98248?
How do I fix CVE-2026-98248?
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-2026-98248 being exploited?
There is no known exploitation of CVE-2026-98248 in the wild and no public exploit code.
Sources
Also known as AZL-106329, BELL-CVE-2026-98248, DEBIAN-CVE-2026-98248, GHSA-p97v-423w-mpcq, UBUNTU-CVE-2026-98248.