CVE-2026-98469 KVM: arm64: Fix AArch32 DBGBXVR<n> handling
A guest VM can crash the host kernel by accessing specific debug registers, 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-2026-98469?
CVE-2026-98469 is a high-severity denial of service 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:
KVM: arm64: Fix AArch32 DBGBXVR<n> handling
The consolidation of the breakpoint and watchpoint register accessors switched DBGBXVR<n> from trap_bvr() to trap_dbg_wb_reg(). The latter selects backing storage with demux_wb_reg(), which only handles Op2 values 4 through 7. Since DBGBXVR<n> uses Op2 1, an AArch32 guest access hits KVM_BUG_ON() and marks the VM dead.
DBGBXVR<n> aliases DBGBVR<n>_EL1[63:32], and its AA32(HI) descriptor already selects the upper half. Map Op2 1 to dbg_bvr[] alongside Op2 4, restoring the pre-regression behavior.
Which versions are affected by CVE-2026-98469?
How do I fix CVE-2026-98469?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-98469 being exploited?
There is no known exploitation of CVE-2026-98469 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-98469, DEBIAN-CVE-2026-98469, GHSA-vcw8-qqhm-h682, UBUNTU-CVE-2026-98469.