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...

Zapscape

KVM エスケープ三部作 ITScape CVE‑2026‑46316 | Januscape CVE‑2026‑53359 | Zapscape CVE‑2026‑64561 ---|---|--- Zapscape: KVM/x86 におけるゲストからホストへのエスケープ 概要 この文書は、Hyunwoo Kim @v4bel によって発見され、報告された Zapscape CVE-2026-64561 脆弱性について説明します。これは KVM/x86 環境において、ゲストがホストへエスケープし、カーネル root 権限でホスト上でコマンドを実行できるようにする KVM...

hyperv_local_dos_poc

Hyper-V DoS PoC。 これはVisual Studio 2019ドライバプロジェクトのコードファイルです。 1. ドライバをコンパイルします。 2. 次のコマンドを使用して、ゲストOSのネストされた仮想化を有効にします: root@kitploit: Set-VMProcessor -VMName -ExposeVirtualizationExtensions $true 3. ゲストOS内でドライバを実行します。ホストOSが再起動されるか、HYPERVISORERRORコードでBSODが発生します。 バグはHyper-V（Windows Server...

CVE-2021-3656-Demo

CVE-2021-3656: この問題は、virtext VMCB フィールドの検証が欠落しているために発生し、悪意のある L1 ゲストが L2 ゲストの VMLOAD/VMSAVE インターセプトと VLS Virtual VMLOAD/VMSAVE の両方を無効にできるようになります。このような状況では、L2 ゲストは VMLOAD/VMSAVE をインターセプトなしで実行でき、ホストの物理メモリの一部を読み書きできます。 Linux カーネルにアクセスするための環境セットアップ: 1. Docker コンテナまたは仮想マシンを使用できます。私は docker コンテナでやってみます...

New Linux Kernel Flaw Gives ARM64 KVM Guests Read-Write Access to Host Memory

A new flaw in the Linux kernel's KVM virtualization code for ARM64 processors can leave a freed piece of host memory exposed to a guest virtual machine on hosts with nested virtualization enabled. The bug, tracked as CVE-2026-89775, allows a guest to read and write host kernel memory, and the...

KVM-Januscape

KVM-XJ ホットパッチ dumptool.py はオフセットを自動検索するためのものです。使い方はコードを見てください。 脆弱性概要 CVE-2026-53359（Januscape）は、Linux カーネル KVM シャドウ MMU における Use-After-Free（UAF）脆弱性です。 潜伏期間：16 年（2010年8月～2026年7月） 影響範囲：ネステッド仮想化を有効にしたすべての Intel/AMD x86 システム 危険度：高、VM 内の root ユーザーがホストに脱出し、ホストの root 権限を取得可能...

CVE-2026-64561

CVE-2026-64561 — Zapscape:KVM/x86 shadow MMU UAF、guest から host root へのエスケープ HackSpeak 配布ミラー。本リポジトリは、研究者 Hyunwoo Kim@v4belが公開した完全な PoC + 技術ドキュメントの配布ミラーです 。コードとドキュメントはアップストリームと一致しています。 ⚠️ アップストリームには LICENSE が付属していません :本ミラーは配布の慣例に従い MIT License,Copyright c 2026 HackSpeak を採用しています。ソースコードの著作権は原作者 V4bel...

kernel: KVM: x86: Don't (re)check L1 intercepts when completing userspace I/O

A flaw was found in the Kernel-based Virtual Machine KVM for x86. This vulnerability occurs when KVM incorrectly re-checks Level 1 L1 intercepts during the completion of userspace I/O emulation for a Level 2 L2 instruction. If the L1 or host userspace modifies I/O interception settings during thi...

DEBIAN-CVE-2026-89929

In the Linux kernel, the following vulnerability has been resolved: KVM: nVM: Ensure INVVPID is emulated on the correct physical CPU When emulating INVVPID, KVM executes INVVPID on the physical CPU using vpid02 instead of the L1 assigned VPID, after doing some validations on the operands. However...

AZL-101610 CVE-2026-89932 affecting package kernel 6.6.152.1-1

In the Linux kernel, the following vulnerability has been resolved: KVM: nVMX: Always flush vpid02 on first use Make sure vpid02 is always flushed on first use by setting lastvpid=0 when allocating vpid02. nestedvmxtransitiontlbflush will always detect a VPID change on first VM-Enter after VMXON,...

CVE-2026-89932 KVM: nVMX: Always flush vpid02 on first use

In the Linux kernel, the following vulnerability has been resolved: KVM: nVMX: Always flush vpid02 on first use Make sure vpid02 is always flushed on first use by setting lastvpid=0 when allocating vpid02. nestedvmxtransitiontlbflush will always detect a VPID change on first VM-Enter after VMXON,...

EUVD-2026-80532

In the Linux kernel, the following vulnerability has been resolved: KVM: nVMX: Always flush vpid02 on first use Make sure vpid02 is always flushed on first use by setting lastvpid=0 when allocating vpid02. nestedvmxtransitiontlbflush will always detect a VPID change on first VM-Enter after VMXON,...

CVE-2026-89929

CVE-2026-89929 affects the Linux kernel KVM subsystem, specifically the nested virtualization (nVM ) code path that emulates the INVVPID instruction. When a guest L1 vCPU migrates between physical CPUs and issues INVVPID, KVM executes the instruction on the current physical CPU rather than the on...

CVE-2026-89929: Undefined Security Weakness

In the Linux kernel, the following vulnerability has been resolved: KVM: nVM: Ensure INVVPID is emulated on the correct physical CPU When emulating INVVPID, KVM executes INVVPID on the physical CPU using vpid02 instead of the L1 assigned VPID, after doing some validations on the operands. However...

Linux Distros Unpatched Vulnerability : CVE-2026-89929

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - KVM: nVM: Ensure INVVPID is emulated on the correct physical CPU When emulating INVVPID, KVM executes INVVPID on the physical CPU using vpid02 instead of the L1...

kernel: KVM: nSVM: Always use vmcb01 in VMLOAD/VMSAVE emulation

A flaw was found in the Linux kernel's Kernel-based Virtual Machine KVM nSVM module. When a nested virtual machine L2 guest executes VMSAVE/VMLOAD instructions, and these are not intercepted by the first-level hypervisor L1, KVM incorrectly uses vmcb02 instead of vmcb01 for managing guest state...

kernel: KVM: nSVM: Always use vmcb01 in VMLOAD/VMSAVE emulation

A flaw was found in the Linux kernel's Kernel-based Virtual Machine KVM nSVM module. When a nested virtual machine L2 guest executes VMSAVE/VMLOAD instructions, and these are not intercepted by the first-level hypervisor L1, KVM incorrectly uses vmcb02 instead of vmcb01 for managing guest state...

Astra Linux – Vulnerability in Linux

A flaw was discovered in the KVM’s AMD code, which handles SVM nested virtualization. The flaw occurs during the processing of the VMCB virtual machine control block provided by the L1 guest to spawn/handle a nested guest L2. Due to improper validation of the “virtext” field, this issue could all...

Astra Linux – Vulnerability in Linux 5.15

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Warns when a triple fault assertion never “escapes” from L2 The warnings are removed because they perform a sanity check that ensures KVM never allows a triple fault in L2 to escape and end up in L1. In normal operation...

Astra Linux – Vulnerability in Linux

A flaw was discovered in the KVM’s AMD code, responsible for supporting SVM nested virtualization. The flaw occurs during the processing of the VMCB virtual machine control block provided by the L1 guest, which is used to spawn or handle a nested guest L2. Due to improper validation of the “intct...