Guest-to-host memory compromise via stale SMM state
Published May 20, 2025 · Updated Aug 5, 2026
State confusion in Linux KVM allows guest OS users to read or write host memory and crash the host through an SMM triple fault. The SVM shutdown_interception path forces INIT without first leaving SMM, preserving an SMM-tagged MMU root while KVM treats the vCPU as outside SMM. Exploitation requires AMD SVM plus guest ring-0 execution or local access to /dev/kvm, and the resulting access crosses the VM boundary.
Summary
What happened
State confusion in Linux KVM allows guest OS users to read or write host memory and crash the host through an SMM triple fault. The SVM shutdown_interception path forces INIT without first leaving SMM, preserving an SMM-tagged MMU root while KVM treats the vCPU as outside SMM. Exploitation requires AMD SVM plus guest ring-0 execution or local access to /dev/kvm, and the resulting access crosses the VM boundary.
The record
- CVE
- CVE-2025-37957
- Published
- May 20, 2025
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 20, 2025CVE publishedPublication date reported by the CVE source.
- Aug 5, 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=5.15.81 <5.16
- Affected versionversion=6.0.11 <6.1
- Affected versionversion=6.1
- Affected versionversion=6425c590d0cc6914658a630a40b7f8226aa028c3
- Affected versionversion=d40ef0a511676bd65ca9acb295430c07af59ab85
- Affected versionversion=ed129ec9057f89d615ba0c81a4984a90345a1684 <a2620f8932fa9fdabc3d78ed6efb004ca409019f
- Affected versionversion=ed129ec9057f89d615ba0c81a4984a90345a1684 <d362b21fefcef7eda8f1cd78a5925735d2b3287c
- Affected versionversion=ed129ec9057f89d615ba0c81a4984a90345a1684 <e9b28bc65fd3a56755ba503258024608292b4ab1
- Affected versionversion=ed129ec9057f89d615ba0c81a4984a90345a1684 <ec24e62a1dd3540ee696314422040180040c1e4a
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
Public exploit references
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Technologies
Your stack
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Your stack
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