{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","favicon":"https://feed.craftedsignal.io/favicon-32x32.png","feed_url":"https://feed.craftedsignal.io/products/kvm/feed.json","home_page_url":"https://feed.craftedsignal.io/","icon":"https://feed.craftedsignal.io/apple-touch-icon.png","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":8.8,"id":"CVE-2026-64561"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["KVM"],"_cs_severities":["medium"],"_cs_tags":["vulnerability","linux","virtualization","informational","privilege-escalation","kernel","kvm","kernel-vulnerability","arm64"],"_cs_type":"advisory","_cs_vendors":["Linux Foundation"],"content_html":"\u003cp\u003eCVE-2026-64561 describes a vulnerability within the Linux Kernel Virtual Machine (KVM) hypervisor on x86 architectures. The issue stems from insufficient validation of root status occurring when making Memory Management Unit (MMU) pages available. In environments where KVM manages guest memory, this logic error in the guest-host interface could potentially lead to memory management inconsistencies or security bypasses. Given the nature of hypervisor vulnerabilities, this issue is most relevant for cloud service providers and environments utilizing containerized or virtualized workloads running on Linux kernels. The impact of such a vulnerability typically involves privilege escalation from the guest to the host or cross-guest information disclosure, though specific exploitation vectors are not currently documented in the public disclosure.\u003c/p\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation could result in memory corruption, unauthorized access to memory regions assigned to other guests, or privilege escalation from a guest virtual machine to the underlying host system, impacting the overall security of multi-tenant virtualized environments.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMonitor the Linux distribution security advisories for the specific kernel versions addressing CVE-2026-64561.\u003c/li\u003e\n\u003cli\u003ePatch the Linux kernel on all host systems running KVM to the version containing the fix for CVE-2026-64561.\u003c/li\u003e\n\u003cli\u003eImplement kernel-level isolation policies for virtual machines where possible to limit the potential blast radius of hypervisor-level flaws.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-08-11T10:43:47Z","date_published":"2026-08-09T09:35:13Z","id":"https://feed.craftedsignal.io/briefs/2026-08-kvm-mmu-vulnerability/","summary":"CVE-2026-64561 identifies a flaw in the Linux KVM hypervisor where incorrect validation of MMU pages could lead to memory management inconsistencies.","title":"Vulnerability in Linux KVM MMU Page Management","url":"https://feed.craftedsignal.io/briefs/2026-08-kvm-mmu-vulnerability/"},{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"id":"CVE-2026-63806"}],"_cs_exploited":true,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["KVM"],"_cs_severities":["medium"],"_cs_tags":["virtualization","denial-of-service","linux","hypervisor"],"_cs_type":"threat","_cs_vendors":["Linux Foundation"],"content_html":"\u003cp\u003eA high-severity denial-of-service vulnerability, identified as CVE-2026-63806, has been discovered in the Kernel-based Virtual Machine (KVM) hypervisor, specifically affecting its \u003ccode\u003eioeventfd\u003c/code\u003e datamatch handling. This flaw allows a malicious or compromised guest virtual machine to intentionally trigger a \u003ccode\u003eBUG_ON()\u003c/code\u003e condition within the host kernel, leading to an immediate crash of the entire KVM host system. The root cause is attributed to incorrect handling of unaligned memory access within the \u003ccode\u003eioeventfd\u003c/code\u003e datamatch logic. The fix involves replacing the problematic \u003ccode\u003eBUG_ON()\u003c/code\u003e with \u003ccode\u003eget_unaligned()\u003c/code\u003e to properly handle such memory operations and prevent the crash. While specific details on active exploitation are not yet available, this vulnerability poses a significant risk to virtualization environments as it enables a guest VM to disrupt the host and all other co-resident guest VMs, making KVM host administrators critical targets for patching.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker gains control over a guest virtual machine running on a vulnerable KVM host.\u003c/li\u003e\n\u003cli\u003eThe malicious guest VM executes specific code designed to interact with KVM's \u003ccode\u003eioeventfd\u003c/code\u003e mechanism.\u003c/li\u003e\n\u003cli\u003eThe guest crafts a particular \u003ccode\u003eioeventfd\u003c/code\u003e operation request targeting the \u003ccode\u003edatamatch\u003c/code\u003e logic within the host.\u003c/li\u003e\n\u003cli\u003eThis crafted operation exploits the vulnerability by causing the host's KVM kernel module to perform an unaligned memory access.\u003c/li\u003e\n\u003cli\u003eDue to the flawed implementation, the unaligned memory access triggers a \u003ccode\u003eBUG_ON()\u003c/code\u003e condition in the host kernel.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003eBUG_ON()\u003c/code\u003e condition causes an immediate and unrecoverable kernel panic, resulting in the KVM host system crashing.\u003c/li\u003e\n\u003cli\u003eThe host system crash leads to a denial of service, rendering all guest virtual machines running on that host inoperable.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-63806 results in a complete denial of service for the KVM host system and all virtual machines running on it. This can lead to significant operational disruption, data loss for applications running within guest VMs, and extended downtime while the host is rebooted and virtual machines are restored. Organizations relying on KVM for critical services are at risk of severe business interruption if this vulnerability is not patched promptly. The scope of impact is critical for any environment utilizing vulnerable KVM hypervisors.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003ePatch CVE-2026-63806 immediately by upgrading your Linux kernel or KVM packages to a version that includes the fix.\u003c/li\u003e\n\u003cli\u003eEnable Syslog or other kernel logging to capture kernel panics and BUG_ON() events from KVM hosts to detect unusual host behavior.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-07-20T07:09:04Z","date_published":"2026-07-20T07:09:04Z","id":"https://feed.craftedsignal.io/briefs/2026-07-kvm-dos-cve-2026-63806/","summary":"A denial-of-service vulnerability (CVE-2026-63806) has been identified in KVM's ioeventfd datamatch handling, allowing a guest virtual machine to trigger a BUG_ON() condition on the host, leading to a system crash.","title":"KVM Guest-Triggerable Denial-of-Service Vulnerability (CVE-2026-63806)","url":"https://feed.craftedsignal.io/briefs/2026-07-kvm-dos-cve-2026-63806/"},{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"id":"CVE-2026-53359"}],"_cs_exploited":true,"_cs_has_poc":true,"_cs_poc_references":["https://sploitus.com/exploit?id=F266B2BA-C215-59FA-BCBB-CAE7D0733EE0\u0026utm_source=rss\u0026utm_medium=rss"],"_cs_products":["Linux kernel","KVM (x86)","KVM","Ubuntu Linux"],"_cs_severities":["high"],"_cs_tags":["linux","kernel","kvm","virtualization","vulnerability","use-after-free","cve"],"_cs_type":"threat","_cs_vendors":["Linux Foundation","Ubuntu"],"content_html":"\u003cp\u003eBased on the CVE-2026-53359 entry, this is a use-after-free vulnerability impacting the Kernel-based Virtual Machine (KVM) virtualization solution on x86 systems. The issue specifically arises within the shadow paging mechanism, a technique KVM uses to efficiently manage guest physical memory for virtual machines. While the provided information from Microsoft Security Response Center (MSRC) is brief, a use-after-free flaw in a hypervisor component like KVM typically allows an attacker with code execution within a guest virtual machine to escalate privileges to the host system. This could lead to a full compromise of the underlying infrastructure, potentially impacting all other virtual machines running on the same host. The vulnerability was published by MSRC on 2026-07-09, indicating it has been publicly disclosed, but the scope of targeting and any observed exploitation remains unspecified in this advisory.\u003c/p\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eA successful exploitation of CVE-2026-53359 could allow a malicious actor, typically with guest OS privileges, to escape the virtual machine and execute arbitrary code on the underlying KVM host. This host compromise would grant the attacker full control over the physical server, enabling them to access sensitive data, disrupt services, or launch further attacks against other virtualized resources. Such an impact is severe, particularly for cloud providers, data centers, or any organization relying on KVM virtualization for their infrastructure. While specific victim counts or targeted sectors are not indicated, the broad adoption of KVM makes this a significant vulnerability.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eApply the latest security updates for the Linux kernel and KVM components containing the fix for CVE-2026-53359 immediately upon release to mitigate the use-after-free vulnerability.\u003c/li\u003e\n\u003cli\u003eMonitor official Linux kernel and KVM project advisories for further details regarding CVE-2026-53359, including any proofs-of-concept or active exploitation reports, to inform patching urgency.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-07-15T12:00:53Z","date_published":"2026-07-09T07:38:41Z","id":"https://feed.craftedsignal.io/briefs/2026-07-kvm-use-after-free/","summary":"CVE-2026-53359 is a high-severity use-after-free vulnerability affecting the KVM virtualization component on x86 architectures within the Linux kernel, stemming from an unexpected role in shadow paging, which could lead to host system compromise.","title":"CVE-2026-53359: KVM x86 Use-After-Free in Shadow Paging","url":"https://feed.craftedsignal.io/briefs/2026-07-kvm-use-after-free/"}],"language":"en","title":"CraftedSignal Threat Feed - KVM","version":"https://jsonfeed.org/version/1.1"}