CVE-2026-63940
Description
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Windows Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63940
- 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
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.