CVE-2026-42493: x86 shadow paging is deprecated
Addressing certain issues, in particular related to operations which may take excessively long and therefore would need preemption, has turned out overly costly. Since alternatives (HVM/PVH: HAP, PV: shim) are commonly available, the decision was to deprecate the functionality, while still retaining it for people to use at their own (security) risk. Memory-wise small enough guests may still be okay to run.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-42493?
CVE-2026-42493 has a risk score of 23, indicating a high-security concern.
How do I fix CVE-2026-42493?
To address CVE-2026-42493, it is recommended to transition away from x86 shadow paging and utilize available alternatives like HVM/PVH or PV.
What impact does CVE-2026-42493 have on QEMU users?
CVE-2026-42493 may lead to performance issues and increased costs due to deprecated functionality in QEMU's x86 shadow paging.
Is x86 shadow paging still supported after CVE-2026-42493?
With CVE-2026-42493, x86 shadow paging is deprecated, meaning it is no longer recommended for use or actively supported.
What alternatives are available for x86 shadow paging in light of CVE-2026-42493?
Alternatives to x86 shadow paging include HVM/PVH with HAP and PV with shim.