--- id: "CVE-2026-98469" kind: "vulnerability" aliases: ["CVE-2026-98469"] title: "Linux KVM: AArch32 guest breakpoint access kills the virtual machine" severity: "unknown" cvss: null epss: null exploited: false status: "open" category: "infrastructure" products: [] ecosystems: [] tags: ["arm64", "infrastructure", "kvm", "linux"] not_affected_if: [] published_at: "2026-10-18T16:16:57+00:00" first_seen_at: "2026-10-23T21:57:15+00:00" updated_at: "2026-10-25T05:26:02+00:00" sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98469", "first_seen_at": "2026-10-23T21:57:15+00:00"}] --- # Linux KVM: AArch32 guest breakpoint access kills the virtual machine The Linux kernel's arm64 KVM code mishandles AArch32 guest accesses to the DBGBXVR breakpoint registers after a refactor. The access triggers a kernel BUG and marks the virtual machine dead. _Summary, check and fix written by a model from the sources; labelled as such._ ## Timeline - 2026-10-23T21:57:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98469 ## From the sources In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix AArch32 DBGBXVR handling The consolidation of the breakpoint and watchpoint register accessors switched DBGBXVR 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 uses Op2 1, an AArch32 guest access hits KVM_BUG_ON() and marks the VM dead. DBGBXVR aliases DBGBVR_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. --- _Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_