KVM: x86/mmu: Check write tracking in all address spaces (CVE-2026-98164) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-98164

KVM: x86/mmu: Check write tracking in all address spaces

Answer in brief

CVE-2026-98164 records a Unknown severity vulnerability in KVM: x86/mmu: Check write tracking in all address spaces. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 29, 2026Updated Sep 29, 2026Source checked Sep 29, 2026First seen by HOL Sep 29, 2026Material review Sep 29, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=699023e239658e62da6f42f47d31b54788521ec1 <09aa68552d2542cc6c23edd1568ac265dc5d886f \|\| >=699023e239658e62da6f42f47d31b54788521ec1 <429b6f43b4d8c98988fdca99e02dc156134e3d77 \|\| >=699023e239658e62da6f42f47d31b54788521ec1 <d8636c8f9f95d0fd1e2f6f1cad0d5757aa6f212a \|\| >=699023e239658e62da6f42f47d31b54788521ec1 <c0a9bd5fca0b5f2dea32b0fc31350e71e8648112 \|\| >=699023e239658e62da6f42f47d31b54788521ec1 <ec8fcaf354c1cbb36755d48e9f5a00c9591349e5 \|\| >=699023e239658e62da6f42f47d31b54788521ec1 <0f38453cdb2e17566ccb7c0f3dabd5bd21caca26	09aa68552d2542cc6c23edd1568ac265dc5d886f, 429b6f43b4d8c98988fdca99e02dc156134e3d77, d8636c8f9f95d0fd1e2f6f1cad0d5757aa6f212a, c0a9bd5fca0b5f2dea32b0fc31350e71e8648112, ec8fcaf354c1cbb36755d48e9f5a00c9591349e5, 0f38453cdb2e17566ccb7c0f3dabd5bd21caca26
Linux/Linuxgeneric	4.2	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 09aa68552d2542cc6c23edd1568ac265dc5d886f if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 29, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Check write tracking in all address spaces kvm_gfn_is_write_tracked() checks only the supplied memslot, but page tracking is per-address-space and shadow pages are shared across all address spaces. With SMM, a GFN can therefore be write-tracked in one address space and appear untracked through the other. Check the supplied slot first, then the slot for the other address space. This ensures all callers honor write tracking regardless of the active address space. In particular, it prevents mmu_try_to_unsync_pages() from marking an upper-level shadow page unsync and eventually triggering the BUG in pte_list_remove(). [invert direction of the conditional. - Paolo]

Quoted source text, attributed separately from HOL analysis.