{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-64561 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-64561 is a high-severity vulnerability in Linux, published on 4 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-64561 and fix it if it is affected.\n\nWhat it is: CVE-2026-64561 is a high-severity vulnerability in Linux, published on 4 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-64561 in the wild and no public exploit code.\n\nAffected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-64561/ (Markdown: https://insights.sbomify.com/CVE-2026-64561/index.md)","id":"CVE-2026-64561","markdown":"https://insights.sbomify.com/CVE-2026-64561/index.md","name":"CVE-2026-64561","record":{"aliases":["AZL-94368","BELL-CVE-2026-64561","DEBIAN-CVE-2026-64561","GHSA-hp26-g45f-hxp5","OESA-2026-3709","UBUNTU-CVE-2026-64561"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","code_execution"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel KVM","requires_auth":"low_privilege","summary":"A race condition in KVM's shadow MMU allows mapping memory into invalid roots, potentially causing system crashes or arbitrary code execution.","user_interaction":"not_required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":8.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-362","name":"Concurrent Execution using Shared Resource with Improper Synchronization"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Check for invalid/obsolete root *after* making MMU pages available\n\nCheck for a \"stale\" page fault, i.e. for an invalid and/or obsolete root,\nafter making MMU pages available for the shadow MMU.  If reclaiming shadow\npages zaps an in-use root, i.e. marks it invalid, then KVM will attempt to\nmap memory into an invalid root.  On its own, populating an invalid root is\n\"fine\", but because child shadow pages inherit their parent's role, any\nchildren created during the map/fetch will be created as invalid pages,\nthus violating KVM's invariant that invalid pages are never on the list of\nactive MMU pages.\n\nNote, the underlying flaw has existed since KVM first started tracking\ninvalid roots in 2008 (commit 2e53d63acba7, \"KVM: MMU: ignore zapped root\npagetables\"), but the true badness only came along in 2020 (Linux 5.9)\nwith the invariant that invalid shadow pages can't be on the list of\nactive pages.\n\nNote #2, inheriting role.invalid when creating child shadow pages is also\nfar from ideal; that flaw will be addressed separately.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":"2026-08-07","github_poc":8,"max_poc_stars":3,"metasploit":0,"nuclei":0,"refs":[{"date":"2026-08-07T01:28:41Z","kind":"github_poc","ref":"https://github.com/HORKimhab/CVE-2026-64561","stars":3,"title":"CVE-2026-64561"},{"date":"2026-08-07T15:51:07Z","kind":"github_poc","ref":"https://github.com/aarif450/Zapscape","stars":2,"title":"Guest-to-host KVM/x86 escape exploiting CVE-2026-64561, delivering a full PoC chain and analysis for security researchers."},{"date":"2026-08-08T02:13:23Z","kind":"github_poc","ref":"https://github.com/HackSpeak/CVE-2026-64561","stars":2,"title":"Zapscape (CVE-2026-64561) KVM/x86 shadow MMU UAF guest-to-host escape PoC mirror — V4bel/@v4bel, MIT; for authorized security testing"},{"date":"2026-08-07T10:05:56Z","kind":"github_poc","ref":"https://github.com/Aoripus-LTD/Zapscape-Fix","stars":1,"title":"Generic kernel live patch for the KVM/x86 shadow-MMU use-after-free (Zapscape, CVE-2026-64561)"},{"date":"2026-08-07T09:36:44Z","kind":"github_poc","ref":"https://github.com/suominen/zapscape","stars":0,"title":"Tracking Zapscape (CVE-2026-64561), the KVM/x86 shadow-MMU guest-to-host escape"},{"date":"2026-08-07T15:52:42Z","kind":"github_poc","ref":"https://github.com/aarif450/aarif450.github.io","stars":0,"title":"Exploit KVM/x86 guest-to-host escape CVE-2026-64561 with Zapscape, a proof-of-concept demonstrating hypervisor vulnerability."},{"date":"2026-08-08T15:49:30Z","kind":"github_poc","ref":"https://github.com/chuzhongyun/CVE-2026-64561-Kernel-Fix","stars":0,"title":"Linux 内核升级指南 - 修复 CVE-2026-64561"},{"date":"2026-10-03T18:40:34Z","kind":"github_poc","ref":"https://github.com/hitechcloud-vietnam/Zapscape","stars":0,"title":"Guest-to-host KVM/x86 escape exploiting CVE-2026-64561, delivering a full PoC chain and analysis for security researchers."}],"tier":"poc_unverified"},"has_fix":true,"headline":"KVM: x86: Check for invalid/obsolete root *after* making MMU pages available","id":"CVE-2026-64561","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"race_condition","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"KVM: nVMX: Hide shadow VMCS right after VMCLEAR","id":"CVE-2026-64562"},"packages":[],"prev":{"headline":"posix-cpu-timers: Prevent UAF caused by non-leader exec() race","id":"CVE-2026-64560"},"products":["Linux"],"published":"2026-08-04","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A race condition in KVM's shadow MMU allows mapping memory into invalid roots, potentially causing system crashes or arbitrary code execution.","url":"https://insights.sbomify.com/CVE-2026-64561/"}