FKIE_CVE-2026-64561

Vulnerability from fkie_nvd - Published: 2026-08-04 07:16 - Updated: 2026-11-03 18:15
Severity
8.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Check for invalid/obsolete root *after* making MMU pages available Check for a "stale" page fault, i.e. for an invalid and/or obsolete root, after making MMU pages available for the shadow MMU. If reclaiming shadow pages zaps an in-use root, i.e. marks it invalid, then KVM will attempt to map memory into an invalid root. On its own, populating an invalid root is "fine", but because child shadow pages inherit their parent's role, any children created during the map/fetch will be created as invalid pages, thus violating KVM's invariant that invalid pages are never on the list of active MMU pages. Note, the underlying flaw has existed since KVM first started tracking invalid roots in 2008 (commit 2e53d63acba7, "KVM: MMU: ignore zapped root pagetables"), but the true badness only came along in 2020 (Linux 5.9) with the invariant that invalid shadow pages can't be on the list of active pages. Note #2, inheriting role.invalid when creating child shadow pages is also far from ideal; that flaw will be addressed separately.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0026dbb7de8ea76e97d6edf42fc3cc084564e2bf
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2abd5287f08319fa35764566b15c6e22cb1068db
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/35e77467610c4a37cb0ff54ee56b85f73b1f5700
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/62ef67af1878fa2cd066642f2f59e33ade95f637
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/65c4f7a1028cf01a93a2762d679c289810ede990
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bce0d3c26e2c761a4bf43c8949f333fc7374eb2d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f3477a6a4164f15287444eda685b5f6405dbd1e5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://github.com/V4bel/Zapscape
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/mmu/mmu.c",
            "arch/x86/kvm/mmu/paging_tmpl.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "62ef67af1878fa2cd066642f2f59e33ade95f637",
              "status": "affected",
              "version": "f95eec9bed76d42194c23153cb1cc8f186bf91cb",
              "versionType": "git"
            },
            {
              "lessThan": "65c4f7a1028cf01a93a2762d679c289810ede990",
              "status": "affected",
              "version": "f95eec9bed76d42194c23153cb1cc8f186bf91cb",
              "versionType": "git"
            },
            {
              "lessThan": "35e77467610c4a37cb0ff54ee56b85f73b1f5700",
              "status": "affected",
              "version": "f95eec9bed76d42194c23153cb1cc8f186bf91cb",
              "versionType": "git"
            },
            {
              "lessThan": "0026dbb7de8ea76e97d6edf42fc3cc084564e2bf",
              "status": "affected",
              "version": "f95eec9bed76d42194c23153cb1cc8f186bf91cb",
              "versionType": "git"
            },
            {
              "lessThan": "f3477a6a4164f15287444eda685b5f6405dbd1e5",
              "status": "affected",
              "version": "f95eec9bed76d42194c23153cb1cc8f186bf91cb",
              "versionType": "git"
            },
            {
              "lessThan": "bce0d3c26e2c761a4bf43c8949f333fc7374eb2d",
              "status": "affected",
              "version": "f95eec9bed76d42194c23153cb1cc8f186bf91cb",
              "versionType": "git"
            },
            {
              "lessThan": "2abd5287f08319fa35764566b15c6e22cb1068db",
              "status": "affected",
              "version": "f95eec9bed76d42194c23153cb1cc8f186bf91cb",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/mmu/mmu.c",
            "arch/x86/kvm/mmu/paging_tmpl.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.9"
            },
            {
              "lessThan": "5.9",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.218",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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\u0027s role, any\nchildren created during the map/fetch will be created as invalid pages,\nthus violating KVM\u0027s 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\u0027t 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."
    }
  ],
  "id": "CVE-2026-64561",
  "lastModified": "2026-11-03T18:15:39.353",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.0,
        "impactScore": 6.0,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-64561",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-16T15:42:48.794184Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-04T07:16:30.937",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0026dbb7de8ea76e97d6edf42fc3cc084564e2bf"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2abd5287f08319fa35764566b15c6e22cb1068db"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/35e77467610c4a37cb0ff54ee56b85f73b1f5700"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/62ef67af1878fa2cd066642f2f59e33ade95f637"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/65c4f7a1028cf01a93a2762d679c289810ede990"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/bce0d3c26e2c761a4bf43c8949f333fc7374eb2d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f3477a6a4164f15287444eda685b5f6405dbd1e5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://github.com/V4bel/Zapscape"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-362"
        }
      ],
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary"
    }
  ]
}



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