What is CVE-2026-63939?

CVE-2026-63939 is a critical-severity vulnerability in Linux. CVSS score: 9.3/10. Published 2026-07-19.

How severe is CVE-2026-63939?

Critical severity. CVSS v3 base score is 9.3 out of 10.

Vulnerability in Linux

CVE-2026-63939

In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Compute the correct max length of the in-GHCB scratch area When setting the length of the GHCB scratch area, and the area is in the GHCB shared buffer, set the…

EPSS: 0.002 (12.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.3 (Critical). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Linux — versions 9b54e248d2644be71cb394eb85f31ad99e023a05, 6.11, 0

References

416baaa9-dc9f-4396-8d5f-8c081fb06d67
416baaa9-dc9f-4396-8d5f-8c081fb06d67
416baaa9-dc9f-4396-8d5f-8c081fb06d67
416baaa9-dc9f-4396-8d5f-8c081fb06d67

Frequently asked questions

What is CVE-2026-63939?: CVE-2026-63939 is a critical-severity vulnerability in Linux. CVSS score: 9.3/10. Published 2026-07-19.
How severe is CVE-2026-63939?: Critical severity. CVSS v3 base score is 9.3 out of 10.