CVE-2026-89911 KVM: arm64: Correctly cap TLBI Range to the architural limit
A guest VM can trigger an integer overflow in KVM arm64 TLB invalidation, potentially causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89911?
CVE-2026-89911 is a high-severity vulnerability in Linux, published on 16 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:
KVM: arm64: Correctly cap TLBI Range to the architural limit
TLB Invalidation by Range has a fairly powerful way of encoding pretty large ranges in a small number of bits. This range can be based on an arbitrary VA, which means it is pretty easy for a guest to generate an overflow should the hypervisor be naive enough to add the range to the base...
Make sure the range is capped to the limit dictated by the address bit that determines the VA range. For an IPA invalidation, this is further corrected down the line to ignore the upper range.
Which versions are affected by CVE-2026-89911?
How do I fix CVE-2026-89911?
Apply the vendor's patch.
Is CVE-2026-89911 being exploited?
There is no known exploitation of CVE-2026-89911 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-89911, DEBIAN-CVE-2026-89911, GHSA-jq85-p2x4-26cc, UBUNTU-CVE-2026-89911.