CVE-2026-23402 | Linux Kernel up to 7.0-rc5 KVM spte_to_pfn privilege escalation

VDB-354621 · CVE-2026-23402 · GCVE-0-2026-23402 LINUX KERNEL UP TO 7.0-RC5 KVM SPTE_TO_PFN PRIVILEGE ESCALATION HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 4.4 $0-$5k 1.85+ Summaryinfo A vulnerability, which was classified as critical, has been found in Linux Kernel up to 7.0-rc5. This vulnerability affects the function spte_to_pfn of the component KVM. Performing a manipulation results in an unknown weakness. This vulnerability is identified as CVE-2026-23402. There is not any exploit available. It is advisable to upgrade the affected component. Detailsinfo A vulnerability, which was classified as critical, was found in Linux Kernel up to 7.0-rc5. This affects the function spte_to_pfn of the component KVM. The impact remains unknown. The summary by CVE is: In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Only WARN in direct MMUs when overwriting shadow-present SPTE Adjust KVM's sanity check against overwriting a shadow-present SPTE with a another SPTE with a different target PFN to only apply to direct MMUs, i.e. only to MMUs without shadowed gPTEs. While it's impossible for KVM to overwrite a shadow-present SPTE in response to a guest write, writes from outside the scope of KVM, e.g. from host userspace, aren't detected by KVM's write tracking and so can break KVM's shadow paging rules. ------------[ cut here ]------------ pfn != spte_to_pfn(*sptep) WARNING: arch/x86/kvm/mmu/mmu.c:3069 at mmu_set_spte+0x1e4/0x440 [kvm], CPU#0: vmx_ept_stale_r/872 Modules linked in: kvm_intel kvm irqbypass CPU: 0 UID: 1000 PID: 872 Comm: vmx_ept_stale_r Not tainted 7.0.0-rc2-eafebd2d2ab0-sink-vm #319 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:mmu_set_spte+0x1e4/0x440 [kvm] Call Trace: ept_page_fault+0x535/0x7f0 [kvm] kvm_mmu_do_page_fault+0xee/0x1f0 [kvm] kvm_mmu_page_fault+0x8d/0x620 [kvm] vmx_handle_exit+0x18c/0x5a0 [kvm_intel] kvm_arch_vcpu_ioctl_run+0xc55/0x1c20 [kvm] kvm_vcpu_ioctl+0x2d5/0x980 [kvm] __x64_sys_ioctl+0x8a/0xd0 do_syscall_64+0xb5/0x730 entry_SYSCALL_64_after_hwframe+0x4b/0x53 ---[ end trace 0000000000000000 ]--- The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-23402 since 01/13/2026. The exploitability is told to be difficult. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/01/2026). Upgrading to version 7.0-rc6 eliminates this vulnerability. Applying the patch df83746075778958954aa0460cca55f4b3fc9c02 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version. Productinfo Type Operating System Vendor Linux Name Kernel Version 7.0-rc1 7.0-rc2 7.0-rc3 7.0-rc4 7.0-rc5 License open-source Website Vendor: https://www.kernel.org/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 4.6 VulDB Meta Temp Score: 4.4 VulDB Base Score: 4.6 VulDB Temp Score: 4.4 VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Privilege escalation CWE: Unknown CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Partially Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: Kernel 7.0-rc6 Patch: df83746075778958954aa0460cca55f4b3fc9c02 Timelineinfo 01/13/2026 CVE reserved 04/01/2026 +77 days Advisory disclosed 04/01/2026 +0 days VulDB entry created 04/01/2026 +0 days VulDB entry last update Sourcesinfo Vendor: kernel.org Advisory: git.kernel.org Status: Confirmed CVE: CVE-2026-23402 (🔒) GCVE (CVE): GCVE-0-2026-23402 GCVE (VulDB): GCVE-100-354621 Entryinfo Created: 04/01/2026 11:25 Changes: 04/01/2026 11:25 (58) Complete: 🔍 Cache ID: 99:91B:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸