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CVE

CVE-2026-63940

KVM: SEV: Ignore Port I/O requests of length '0'
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CVE

CVE-2026-63940

KVM: SEV: Ignore Port I/O requests of length '0'

In the Linux kernel, the following vulnerability has been resolved:

KVM: SEV: Ignore Port I/O requests of length '0'

Explicitly ignore Port I/O requests of length '0' (or count '0'), so that

setting up the software scratch area (and other code) doesn't have to

worry about underflowing the length, and to allow for WARNing on trying

to configure the scratch area with len==0.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
9.3
-
3.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
C
H
U
0
-
3.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
C
H
U
-

Related Resources

No items found.

References

https://git.kernel.org/stable/c/2254972d4d69e279ba4e87bf0968eb08ad0d3c92, https://git.kernel.org/stable/c/3988bd2723de407ae90fa7a6f6029b4e60238c58, https://git.kernel.org/stable/c/3b6035bc6bff20e89752ce4358bc4c9a9d5883f2, https://git.kernel.org/stable/c/c30cde934c7813b4e3069765dac64ce3d31e34f2, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63940.json, https://nvd.nist.gov/vuln/detail/CVE-2026-63940, https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Severity

9.3

CVSS Score
0
10

Basic Information

Base CVSS
9.3
EPSS Probability
0.00185%
EPSS Percentile
0.08141%
Introduced Version
291bd20d5d88814a73d43b55b9428feab2f28094,5.11.0,6.13.0,6.19.0,0
Fix Available
3988bd2723de407ae90fa7a6f6029b4e60238c58,6.12.95,6.18.35,7.0.12,6.12.95-1,7.0.0-28.28~24.04.1,7.0.0-1016.16~24.04.1,7.0.0-28.28.1~24.04.3,0:6.12.0-206.104.3.3.el9uek,0:6.12.0-206.104.3.3.el10uek,1:6.18.35-68.127.amzn2023,1:1.0-0.amzn2023

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