Host crash via truncated PMU array size
Published Sep 11, 2026 · Updated Sep 11, 2026
Out-of-bounds access in Linux 6.18 RISC-V KVM allows guest OS users to crash the host through a crafted SBI PMU event query. kvm_riscv_vcpu_pmu_event_info stores num_events times the entry size in 32 bits, allocates the truncated size, then loops over the original count. Exploitation requires a RISC-V KVM host with PMU support and guest control of EVENT_GET_INFO; resulting reads and writes can corrupt memory or stop the host.
Summary
What happened
Out-of-bounds access in Linux 6.18 RISC-V KVM allows guest OS users to crash the host through a crafted SBI PMU event query. kvm_riscv_vcpu_pmu_event_info stores num_events times the entry size in 32 bits, allocates the truncated size, then loops over the original count. Exploitation requires a RISC-V KVM host with PMU support and guest control of EVENT_GET_INFO; resulting reads and writes can corrupt memory or stop the host.
The record
- CVE
- CVE-2026-89513
- Published
- Sep 11, 2026
- Updated
- Sep 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 11, 2026CVE publishedPublication date reported by the CVE source.
- Sep 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=6.18
- Affected versionversion=e309fd113b9f6c34672a487be08fecb7e12e7e29 <735bc20c24187ca419c9d5e63860a54b91be34bd
- Affected versionversion=e309fd113b9f6c34672a487be08fecb7e12e7e29 <82088f88c96b99c27a974d09b02c2b133262fadf
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Technologies
Your stack
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Your stack
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