In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer Use READ_ONCE() when reading entries/indices from the guest-accessible Page State Change buffer to defend against TOCTOU bugs. Don't bother with READ_ONCE()/WRITE_ONCE() for cases where KVM is writing (and not consuming the result!), as the guest isn't supposed to touch the buffer while it's being processed. I.e. using READ_ONCE() is all about protecting against misbehaving guests.

An update of the linux package has been released.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Use READ_ONCE() when reading     entries/indices from PSC buffer Use READ_ONCE() when reading entries/indices from the guest-accessible     Page State Change buffer to defend against TOCTOU bugs. Don't bother with READ_ONCE()/WRITE_ONCE() for     cases where KVM is writing (and not consuming the result!), as the guest isn't supposed to touch the     buffer while it's being processed. I.e. using READ_ONCE() is all about protecting against misbehaving     guests. (CVE-2026-63937)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
335080	openSUSE 16: cluster-md-kmp-64kb / cluster-md-kmp-azure / cluster-md-kmp-default / etc (openSUSE-SU-2026:21555-1)	Nessus	SuSE Local Security Checks	Local	high
333762	Photon OS 5.0: Linux PHSA-2026-5.0-92-0895	Nessus	PhotonOS Local Security Checks	Local	high
328493	Amazon Linux 2023 : bpftool6.12, kernel6.12, kernel6.12-devel (ALAS2023-2026-1968)	Nessus	Amazon Linux Local Security Checks	Local	high
328080	Linux Distros Unpatched Vulnerability : CVE-2026-63937	Nessus	Misc.	Local	high
322944	Photon OS 5.0: Linux PHSA-2026-5.0-0895	Nessus	PhotonOS Local Security Checks	Local	high
322087	Amazon Linux 2023 : bpftool6.18, kernel6.18, kernel6.18-devel (ALAS2023-2026-1881)	Nessus	Amazon Linux Local Security Checks	Local	high

Detections

Analytics

CVE-2026-63937

high

Tenable Plugins

high

high

high

high

high

high