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CVE-2026-64291

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: iommufd: Set veventq_depth upper bound iommufd_veventq_alloc() accepts any !0 veventq_depth from userspace, with an upper bound at U32_MAX. This leaves a vulnerability where userspace can allocate excessively large queues to exhaust kernel memory reserves. Cap the veventq_depth (maximum number of entries) to 1 << 19, matching the maximum number of entries in the SMMUv3 EVTQ (the largest use case today).

Severity
MEDIUM
CVSS score
5.5 (v3.1)
Vulnerability status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-25 10:17:09.837000
Last modified
2026-11-06 17:18:45.850000
View original CVE JSON
{
  "id": "CVE-2026-64291",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-07-25T10:17:09.837",
  "lastModified": "2026-11-06T17:18:45.850",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommufd: Set veventq_depth upper bound\n\niommufd_veventq_alloc() accepts any !0 veventq_depth from userspace, with\nan upper bound at U32_MAX.\n\nThis leaves a vulnerability where userspace can allocate excessively large\nqueues to exhaust kernel memory reserves.\n\nCap the veventq_depth (maximum number of entries) to 1 << 19, matching the\nmaximum number of entries in the SMMUv3 EVTQ (the largest use case today)."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/iommu/iommufd/eventq.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "e36ba5ab808ef6237c3148d469c8238674230e2b",
              "lessThan": "f565297edf316016be4a1a9e2eb9f39359313f43",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "e36ba5ab808ef6237c3148d469c8238674230e2b",
              "lessThan": "e7b5e55652746b1221b9c10ff80eae8a154101ba",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "e36ba5ab808ef6237c3148d469c8238674230e2b",
              "lessThan": "6ebf2eb46fbd5b40393ff8fbb847ba96925beaff",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/iommu/iommufd/eventq.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.15",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.15",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.39",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.4",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-11-06T16:34:03.370926Z",
          "id": "CVE-2026-64291",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.15",
              "versionEndExcluding": "6.18.39",
              "matchCriteriaId": "1DA3E752-10DF-4260-A04E-FB6A07086768"
            },
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "versionStartIncluding": "6.19",
              "versionEndExcluding": "7.1.4",
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  "references": [
    {
      "url": "https://git.kernel.org/stable/c/6ebf2eb46fbd5b40393ff8fbb847ba96925beaff",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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    {
      "url": "https://git.kernel.org/stable/c/f565297edf316016be4a1a9e2eb9f39359313f43",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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}