Answer in brief
CVE-2026-64284 records a Unknown severity vulnerability in KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits. 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.
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.
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 | >=f7f39c50edb9d336274371953275e0d3503b9b75 <b3436d9b9b1affe1c3191ac9831308923f5f03c3 || >=f7f39c50edb9d336274371953275e0d3503b9b75 <4ad73ef0e7966ecfe67de0060537b4cb14d9acd4 || >=f7f39c50edb9d336274371953275e0d3503b9b75 <f2ca2b5326211bd38490f0497eb583721ce0bbc0 || >=f7f39c50edb9d336274371953275e0d3503b9b75 <0ffedf43910e44b76c2c1db4e9fbf12b268190c1 | b3436d9b9b1affe1c3191ac9831308923f5f03c3, 4ad73ef0e7966ecfe67de0060537b4cb14d9acd4, f2ca2b5326211bd38490f0497eb583721ce0bbc0, 0ffedf43910e44b76c2c1db4e9fbf12b268190c1 |
| Linux/Linuxgeneric | 6.12 | Not reported |
Published upstream
Jul 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits Move the handling of fastpath userspace exits into vendor code to ensure KVM runs vendor specific operations that need to run before userspace gains control of the vCPU. E.g. for VMX (and soon to be for SVM as well), KVM needs to flush the PML buffer prior to exiting to userspace, otherwise any memory written by the final KVM_RUN might never be flagged as dirty. Note, waiting to snapshot CR0 and CR3 until svm_handle_exit() is flawed in general, as that risks consuming stale state in a fastpath handler. That will be addressed in a future change.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-64284 records a Unknown severity vulnerability in KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits. 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.
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.
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 | >=f7f39c50edb9d336274371953275e0d3503b9b75 <b3436d9b9b1affe1c3191ac9831308923f5f03c3 || >=f7f39c50edb9d336274371953275e0d3503b9b75 <4ad73ef0e7966ecfe67de0060537b4cb14d9acd4 || >=f7f39c50edb9d336274371953275e0d3503b9b75 <f2ca2b5326211bd38490f0497eb583721ce0bbc0 || >=f7f39c50edb9d336274371953275e0d3503b9b75 <0ffedf43910e44b76c2c1db4e9fbf12b268190c1 | b3436d9b9b1affe1c3191ac9831308923f5f03c3, 4ad73ef0e7966ecfe67de0060537b4cb14d9acd4, f2ca2b5326211bd38490f0497eb583721ce0bbc0, 0ffedf43910e44b76c2c1db4e9fbf12b268190c1 |
| Linux/Linuxgeneric | 6.12 | Not reported |
Published upstream
Jul 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits Move the handling of fastpath userspace exits into vendor code to ensure KVM runs vendor specific operations that need to run before userspace gains control of the vCPU. E.g. for VMX (and soon to be for SVM as well), KVM needs to flush the PML buffer prior to exiting to userspace, otherwise any memory written by the final KVM_RUN might never be flagged as dirty. Note, waiting to snapshot CR0 and CR3 until svm_handle_exit() is flawed in general, as that risks consuming stale state in a fastpath handler. That will be addressed in a future change.
Quoted source text, attributed separately from HOL analysis.