Incorrect AArch32 debug register handling in Linux KVM arm64
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
The Linux kernel from 6.14 contains a flaw in the KVM arm64 handling of AArch32 DBGBXVR<n> registers. Op2 value 1 is not mapped to backing storage, so an AArch32 guest access triggers a kernel bug check that marks the virtual machine dead. A local user with no privileges can trigger the failure, which affects host availability.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Upgrade to Linux kernel 6.18.55, 7.2.9 or 7.3, which contain the fix. Red Hat lists Red Hat Enterprise Linux 10 as affected, with no fix available.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 6.18.55, 7.2.9, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
Not affected: 6 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-18 Threatist record created from CVE-2026-98469
- 2026-10-18 Alias added: GHSA-vcw8-qqhm-h682
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-20 Affected versions changed · Red Hat
- 2026-10-20 CVSS score added · Red Hat
- 2026-10-24 CVSS score added · CNA
- 2026-10-30 Affected versions changed · Red Hat
References
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Sources
- CVE-2026-98469 · CVE Program
- CVE-2026-98469 · NVD
- FIRST EPSS
- GHSA-vcw8-qqhm-h682 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98469 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences