CVE Catalog

CVE-2026-64285

MediumCVSS 5.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.14%

4th percentile - higher than 4% of all known CVEs

Summary

In the Linux kernel KVM for AMD SEV, a vulnerability was found due to not pinning the source page for write when adding CPUID data for an SNP guest. KVM writes back corrected CPUID data, but if the page is read-only, it can clobber read-only memory.

Risk Assessment

An attacker can cause overwriting of read-only memory, potentially leading to unpredictable system behavior or privilege escalation.

Recommendation

Apply the patch that acquires a writable pin on the source page before writing CPUID data.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Pin source page for write when adding CPUID data for SNP guest When populating a guest_memfd instance with the initial CPUID data for an SNP guest, acquire a writable pin on the source page as KVM will write back the "correct" CPUID information if the userspace provided data is rejected by trusted firmware. Because KVM writes to the source page using a kernel mapping, pinning for read could result in KVM clobbering read-only memory. Note, well-behaved VMMs are unlikely to be affected, as CPUID information is almost always dynamically generated by userspace, i.e. it's unlikely for the CPUID information to be backed by a read-only mapping. [sean: rewrite shortlog and changelog, tag for stable@]

Vulnerability data from NVD (NIST) · CISA KEV · EPSS