CVE-2025-38560

x86/sev: Evict cache lines during SNP memory validation

Published Aug 19, 2025 CVSS 3.1 · 9.3 Critical EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

x86/sev: Evict cache lines during SNP memory validation

An SNP cache coherency vulnerability requires a cache line eviction
mitigation when validating memory after a page state change to private.
The specific mitigation is to touch the first and last byte of each 4K
page that is being validated. There is no need to perform the mitigation
when performing a page state change to shared and rescinding validation.

CPUID bit Fn8000001F_EBX[31] defines the COHERENCY_SFW_NO CPUID bit
that, when set, indicates that the software mitigation for this
vulnerability is not needed.

Implement the mitigation and invoke it when validating memory (making it
private) and the COHERENCY_SFW_NO bit is not set, indicating the SNP
guest is vulnerable.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4328-1 linux-6.1 security update
EUVD EUVD EUVD-2025-27903 In the Linux kernel, the following vulnerability has been resolved: x86/sev: Evict cache lines during SNP memory validation An SNP cache coherency vulnerability requires a cache line eviction mitigation when validating memory after a page state change to private. The specific mitigation is to touch the first and last byte of each 4K page that is being validated. There is no need to perform the mitigation when performing a page state change to shared and rescinding validation. CPUID bit Fn8000001F_EBX[31] defines the COHERENCY_SFW_NO CPUID bit that, when set, indicates that the software mitigation for this vulnerability is not needed. Implement the mitigation and invoke it when validating memory (making it private) and the COHERENCY_SFW_NO bit is not set, indicating the SNP guest is vulnerable.
Ubuntu USN Ubuntu USN USN-7879-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7879-2 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7880-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7879-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7879-4 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7934-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-2 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-8031-1 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-3 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-4 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-5 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8031-2 Linux kernel (GCP FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-6 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-8031-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8052-1 Linux kernel (Low Latency) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-7 Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-8028-8 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8052-2 Linux kernel (Xilinx) vulnerabilities
Ubuntu USN Ubuntu USN USN-8074-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8074-2 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8126-1 Linux kernel (Azure) vulnerabilities
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 9.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'}

Type Values Removed Values Added
First Time appeared Debian
Debian debian Linux
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*
Vendors & Products Debian
Debian debian Linux
Type Values Removed Values Added
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel
Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: x86/sev: Evict cache lines during SNP memory validation An SNP cache coherency vulnerability requires a cache line eviction mitigation when validating memory after a page state change to private. The specific mitigation is to touch the first and last byte of each 4K page that is being validated. There is no need to perform the mitigation when performing a page state change to shared and rescinding validation. CPUID bit Fn8000001F_EBX[31] defines the COHERENCY_SFW_NO CPUID bit that, when set, indicates that the software mitigation for this vulnerability is not needed. Implement the mitigation and invoke it when validating memory (making it private) and the COHERENCY_SFW_NO bit is not set, indicating the SNP guest is vulnerable.
Title x86/sev: Evict cache lines during SNP memory validation
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 15, 2026, 9:52 PM
Reserved
Apr 16, 2025, 4:51 AM
Status
Modified
Published
Aug 19, 2025, 5:15 PM
Modified
Oct 15, 2026, 10:18 PM
Severity
Moderate
Public date
Aug 19, 2025, 12:00 AM