Answer in brief
CVE-2026-89915 records a Critical severity (CVSS 9.3) vulnerability in KVM: arm64: Remove VM-wide VNCR mapping counter. 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.
CVSS is 9.3. 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.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=4ffa72ad8f37e73bbb6c0baa88557bcb4fd39929 <5453b85c7ebb605febac3df42021f9471663f051 || >=4ffa72ad8f37e73bbb6c0baa88557bcb4fd39929 <87c2bbf189829dce4aaada8f82e3d54ccc037976 || >=4ffa72ad8f37e73bbb6c0baa88557bcb4fd39929 <c55bc773b6e814406658fae7dc5c15f639ed816e | 5453b85c7ebb605febac3df42021f9471663f051, 87c2bbf189829dce4aaada8f82e3d54ccc037976, c55bc773b6e814406658fae7dc5c15f639ed816e |
| Linux/Linuxgeneric | 6.16 | Not reported |
Published upstream
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 16, 2026
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Remove VM-wide VNCR mapping counter The global VNCR mapping counter is used to decide whether an L1 provided VNCR page is mapped in L0 on any CPU at the point of dealing with a TLB invalidation. It is incremented when a mapping is made in the fixmap, and decremented when unmapped. As it turns out, this tracking has several flaws: - we are trying to invalidate TLBs, and the mapping is only an opportunistic consequence of the TLB. Checking this counter to decide whether a TLB needs to be invalidated may result in missed invalidations. - an L1 vcpu invalidating its own TLB (a very likely case) will not succeed in invalidating the VNCR pseudo TLB because that page is not mapped in L0 at this stage. Given that this tracking fails at delivering the minimum guarantees that are required and is only a performance optimisation, remove it completely.
Quoted source text, attributed separately from HOL analysis.