CVE-2026-90121 irqchip/gic-v5: Clear per-CPU IRS data on teardown
A use-after-free vulnerability in the Linux kernel GIC-v5 driver allows local attackers to execute arbitrary code or escalate privileges via stale per-CPU pointers.
- 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-2026-90121?
CVE-2026-90121 is an use after free vulnerability in Linux, published on 17 Sep 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:
irqchip/gic-v5: Clear per-CPU IRS data on teardown
IRS affinity setup publishes an IRS pointer and IAFFID state in the per-CPU data before the remaining IRS initialization can fail. The error path then frees the IRS data without clearing that published state, leaving CPUs associated with freed memory.
On initialization failure and normal IRS teardown, clear the per-CPU IRS association by removing the stale pointer to irs_data. Also invalidate the per-CPU IAFFID state for any CPUs that were tied to the IRS before it was freed.
Which versions are affected by CVE-2026-90121?
How do I fix CVE-2026-90121?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-90121 being exploited?
There is no known exploitation of CVE-2026-90121 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-90121, DEBIAN-CVE-2026-90121, GHSA-fx3f-7rrv-pccf, UBUNTU-CVE-2026-90121.