Januscape

Januscape: Guest-to-Host Escape in KVM/x86 Abstract This document describes the Januscape CVE-2026-53359 vulnerability discovered and reported by Hyunwoo Kim @v4bel. It is a KVM escape vulnerability that lets a guest escape to the host in a KVM/x86 environment. To the best of public knowledge, th...

Astra Linux – vulnerability in linux-6.1

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Update x2APIC MSR intercepts if AVIC is inhibited while L2 is active Always update x2APIC MSR intercepts for L1 when AVIC is deactivated, even if L2 is active and KVM is using a separate MSR bitmap to run L2. If AVIC is...

Zapscape

The KVM Escape Trilogy ITScape CVE‑2026‑46316 | Januscape CVE‑2026‑53359 | Zapscape CVE‑2026‑64561 ---|---|--- Zapscape: Guest-to-Host Escape in KVM/x86 Abstract This document describes the Zapscape CVE-2026-64561 vulnerability discovered and reported by Hyunwoo Kim @v4bel. It is a KVM escape...

CVE-2026-64561

CVE-2026-64561 — Zapscape: KVM/x86 shadow MMU UAF, guest escape to host root HackSpeak distribution mirror. This repository is a distribution mirror of the complete PoC + technical write-up publicly released by researcher Hyunwoo Kim @v4bel , with code and documentation identical to upstream. ⚠️...

KVM-Januscape

KVM-XJ Hot Patch dumptool.py automatically finds offsets; how to use it? Just read the code. Vulnerability Overview CVE-2026-53359 Januscape is a use-after-free UAF vulnerability in the Linux kernel KVM shadow MMU. Lurking time : 16 years August 2010 to July 2026 Affected range : All Intel/AMD x8...

CVE-2021-3656-Demo

CVE-2021-3656: This issue is caused by missing validation of the the virtext VMCB field and allows a malicious L1 guest to disable both VMLOAD/VMSAVE intercepts and VLS Virtual VMLOAD/VMSAVE for the L2 guest. Under these circumstances, the L2 guest is able to run VMLOAD/VMSAVE unintercepted, and...

hyperv_local_dos_poc

Hyper-V DoS PoC. This is code files of Visual Studio 2019 driver project. 1. Compile driver. 2. Enable nested virtualization for guest OS using command: Set-VMProcessor -VMName -ExposeVirtualizationExtensions $true 3. Run driver inside guest OS. Host OS will be rebooted or generate BSOD with...

CVE-2026-99120

A flaw was found in the Linux kernel's KVM Kernel-based Virtual Machine subsystem. Improper validation of error codes generated during nested virtualization memory faults leads to an out-of-bounds read vulnerability. An attacker within a guest virtual machine can exploit this issue by triggering...

CVE-2026-99176

A flaw was found in the Linux kernel's Kernel-based Virtual Machine KVM nested virtualization component. When loading nested virtual machine state fails during certain non-standard entry operations, KVM fails to reset the memory management unit MMU pointer back to the root context. A local user...

CVE-2026-89929

A flaw was found in the Kernel-based Virtual Machine KVM in the Linux kernel. When using nested virtualization, the INVVPID Invalidate Virtual Processor ID instruction may be incorrectly emulated on a different physical CPU than where the guest operating system L2 last ran. This can lead to stale...

CVE-2026-98720

A flaw was found in the Linux kernel's KVM Kernel-based Virtual Machine nested virtualization implementation. This flaw allows an attacker within a nested guest to bypass isolation boundaries and directly access host hardware controls, potentially causing host system instability or a Denial of...

CVE-2026-98716

A flaw was found in the Linux kernel's KVM Kernel-based Virtual Machine subsystem for AMD processors SVM. During nested virtualization, KVM incorrectly checked whether Model-Specific Register MSR accesses were intercepted by referencing the wrong control structure's permission bitmap. A malicious...

SUSE CVE-2026-98720

In the Linux kernel, the following vulnerability has been resolved: KVM: nVMX: Force MSR bitmap refresh if runtime eVMCS controls are modified Force a refresh of the vmcs02 MSR bitmap during nested VM-Enter if the runtime eVMCS controls pin, primary, secondary, etc. are being updated. If L1 isn't...

CVE-2026-98653

A flaw was found in the Linux kernel's Kernel-based Virtual Machine KVM subsystem on s390 architectures. In nested virtualization environments, the kernel can erroneously pass an unhandled memory fault error to host userspace when shadowing nested guest memory pages that are not yet mapped. A gue...

CVE-2026-98639

A flaw was found in the Linux kernel's KVM Kernel-based Virtual Machine subsystem for the RISC-V architecture. During nested virtualization acceleration, control flags are written before the target page parameters are properly committed to shared memory. Consequently, the supervisor interface or...

CVE-2026-98440

A flaw was found in the Linux kernel's Kernel-based Virtual Machine KVM subsystem on ARM64 architectures. In nested virtualization configurations, shadow memory management structures are prematurely freed during shadow page flushes while other parts of the system may still reference them. A local...

Astra Linux – vulnerability in linux-6.12

In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Raise UD if unhandled VMMCALL isn’t intercepted by L1 Explicitly synthesize a UD for VMMCALL if L2 is active, L1 does NOT want to intercept VMMCALL, nestedsvml2tlbflushenabled is true, and the hypercall is something...

CVE-2026-98720

In the Linux kernel, the following vulnerability has been resolved: KVM: nVMX: Force MSR bitmap refresh if runtime eVMCS controls are modified Force a refresh of the vmcs02 MSR bitmap during nested VM-Enter if the runtime eVMCS controls pin, primary, secondary, etc. are being updated. If L1 isn't...

AZL-109266 CVE-2026-98720 affecting package kernel 6.6.161.1-1

In the Linux kernel, the following vulnerability has been resolved: KVM: nVMX: Force MSR bitmap refresh if runtime eVMCS controls are modified Force a refresh of the vmcs02 MSR bitmap during nested VM-Enter if the runtime eVMCS controls pin, primary, secondary, etc. are being updated. If L1 isn't...

DEBIAN-CVE-2026-98720

In the Linux kernel, the following vulnerability has been resolved: KVM: nVMX: Force MSR bitmap refresh if runtime eVMCS controls are modified Force a refresh of the vmcs02 MSR bitmap during nested VM-Enter if the runtime eVMCS controls pin, primary, secondary, etc. are being updated. If L1 isn't...