CVE-2026-63938

CRITICAL 9.3CVE-2026-63938 · Published 19/07/2026 · updated 27/10/2026

In short

CVE-2026-63938 is a CRITICAL (CVSS 9.3) vulnerability.
Chance of exploitation in the next 30 days (EPSS): 0.20%, higher than 9.3% of all vulnerabilities.
No patched version is listed yet: follow the vendor's advisory in References.

Package	Affected versions	Patched versions
—	No affected product versions are listed for this vulnerability yet.

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Check PSC request indices against the actual size of the buffer When processing Page State Change (PSC) requests, validate the PSC buffer against the effective size of the scratch area, which could be less than the maximum size if the guest provided a pointer that isn't exactly at the start of the GHCB shared buffer.

References

git.kernel.org/stable/c/121d88de56bc5c0ba0ce2f6381af67f948a7e7c1 · Patch
git.kernel.org/stable/c/505a3b94535583e4265360e2621734e355ef263d · Patch
git.kernel.org/stable/c/5198f70c09a5f6e9e5f5a0a2c6b388f24294b176 · Patch
git.kernel.org/stable/c/75c8d1d7291268b479794fba5808971dc2f5eaf3 · Patch

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