Host memory corruption via CK machine-check reinjection
Published Sep 16, 2026 · Updated Sep 16, 2026
Memory corruption in Linux KVM for s390 allows attackers to corrupt host memory during CK machine-check reinjection. kvm_s390_reinject_machine_check passes a stack-allocated interrupt record to the floating-interrupt path, whose cleanup calls kfree on that stack address. The condition requires a channel-subsystem damage machine check while an s390 guest is running; the published record does not establish attacker control or effects beyond host memory corruption.
Summary
What happened
Memory corruption in Linux KVM for s390 allows attackers to corrupt host memory during CK machine-check reinjection. kvm_s390_reinject_machine_check passes a stack-allocated interrupt record to the floating-interrupt path, whose cleanup calls kfree on that stack address. The condition requires a channel-subsystem damage machine check while an s390 guest is running; the published record does not establish attacker control or effects beyond host memory corruption.
The record
- CVE
- CVE-2026-89920
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 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=4.13
- Affected versionversion=4d62fcc0b692e3b4058d7d138114c27cd8b011f7 <546dde823a36d7283dcf46127c2f3d093443860f
- Affected versionversion=4d62fcc0b692e3b4058d7d138114c27cd8b011f7 <6ee52d3af2a1bf70349cf3f860933c8d221e229a
- Affected versionversion=4d62fcc0b692e3b4058d7d138114c27cd8b011f7 <7077ec953996acc04b49d1dfc43df1c1a2a74395
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
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Technologies
Your stack
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Your stack
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