CVE-2026-64036 (GCVE-0-2026-64036)

Vulnerability from cvelistv5 – Published: 2026-07-19 15:39 – Updated: 2026-07-20 13:42
VLAI
Title
cgroup/rstat: validate cpu before css_rstat_cpu() access
Summary
In the Linux kernel, the following vulnerability has been resolved: cgroup/rstat: validate cpu before css_rstat_cpu() access css_rstat_updated() is exposed as a BPF kfunc and accepts a caller-provided cpu argument. The function uses cpu for per-cpu rstat lookups without checking whether it refers to a valid possible CPU. A BPF iter/cgroup program with CAP_BPF and CAP_PERFMON can pass an invalid cpu value. On an unfixed UBSCAN_BOUNDS test kernel, cpu == 0x7fffffff triggers: UBSAN: array-index-out-of-bounds in kernel/cgroup/rstat.c:31:9 index 2147483647 is out of range for type 'long unsigned int [64]' Call Trace: css_rstat_updated bpf_iter_run_prog cgroup_iter_seq_show bpf_seq_read Add cpu validation to the BPF-facing css_rstat_updated() kfunc and move the common implementation to __css_rstat_updated() for in-kernel callers.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: a319185be9f5ad13c2a296d448ac52ffe45d194c , < 6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6 (git)
Affected: a319185be9f5ad13c2a296d448ac52ffe45d194c , < fd2bd9fa7700ddf28296486b2598cff2f80cc819 (git)
Affected: a319185be9f5ad13c2a296d448ac52ffe45d194c , < 8817005efbdfdf5d4e4814cb5dc52b53d12917d7 (git)
Create a notification for this product.
Linux Linux Affected: 6.1
Unaffected: 0 , < 6.1 (semver)
Unaffected: 6.18.34 , ≤ 6.18.* (semver)
Unaffected: 7.0.11 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "block/blk-cgroup.c",
            "include/linux/cgroup.h",
            "kernel/cgroup/rstat.c",
            "mm/memcontrol.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6",
              "status": "affected",
              "version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
              "versionType": "git"
            },
            {
              "lessThan": "fd2bd9fa7700ddf28296486b2598cff2f80cc819",
              "status": "affected",
              "version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
              "versionType": "git"
            },
            {
              "lessThan": "8817005efbdfdf5d4e4814cb5dc52b53d12917d7",
              "status": "affected",
              "version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "block/blk-cgroup.c",
            "include/linux/cgroup.h",
            "kernel/cgroup/rstat.c",
            "mm/memcontrol.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.1"
            },
            {
              "lessThan": "6.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.34",
                  "versionStartIncluding": "6.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.11",
                  "versionStartIncluding": "6.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "6.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncgroup/rstat: validate cpu before css_rstat_cpu() access\n\ncss_rstat_updated() is exposed as a BPF kfunc and accepts a\ncaller-provided cpu argument. The function uses cpu for per-cpu rstat\nlookups without checking whether it refers to a valid possible CPU.\n\nA BPF iter/cgroup program with CAP_BPF and CAP_PERFMON can pass an\ninvalid cpu value. On an unfixed UBSCAN_BOUNDS test kernel, cpu ==\n0x7fffffff triggers:\n\n  UBSAN: array-index-out-of-bounds in kernel/cgroup/rstat.c:31:9\n  index 2147483647 is out of range for type \u0027long unsigned int [64]\u0027\n  Call Trace:\n    css_rstat_updated\n    bpf_iter_run_prog\n    cgroup_iter_seq_show\n    bpf_seq_read\n\nAdd cpu validation to the BPF-facing css_rstat_updated() kfunc and\nmove the common implementation to __css_rstat_updated() for in-kernel\ncallers."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-20T13:42:39.799Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6"
        },
        {
          "url": "https://git.kernel.org/stable/c/fd2bd9fa7700ddf28296486b2598cff2f80cc819"
        },
        {
          "url": "https://git.kernel.org/stable/c/8817005efbdfdf5d4e4814cb5dc52b53d12917d7"
        }
      ],
      "title": "cgroup/rstat: validate cpu before css_rstat_cpu() access",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64036",
    "datePublished": "2026-07-19T15:39:24.783Z",
    "dateReserved": "2026-07-19T07:54:57.028Z",
    "dateUpdated": "2026-07-20T13:42:39.799Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-64036",
      "date": "2026-07-21",
      "epss": "0.00127",
      "percentile": "0.02743"
    },
    "microsoft_vex": {
      "current_release_date": "2026-07-21T01:01:29.000Z",
      "cve": "CVE-2026-64036",
      "id": "msrc_CVE-2026-64036",
      "initial_release_date": "2026-07-21T01:01:29.000Z",
      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "cgroup/rstat: validate cpu before css_rstat_cpu() access",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-64036.json",
      "version": "1"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-64036\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-07-19T16:17:43.847\",\"lastModified\":\"2026-07-20T15:17:04.550\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\ncgroup/rstat: validate cpu before css_rstat_cpu() access\\n\\ncss_rstat_updated() is exposed as a BPF kfunc and accepts a\\ncaller-provided cpu argument. The function uses cpu for per-cpu rstat\\nlookups without checking whether it refers to a valid possible CPU.\\n\\nA BPF iter/cgroup program with CAP_BPF and CAP_PERFMON can pass an\\ninvalid cpu value. On an unfixed UBSCAN_BOUNDS test kernel, cpu ==\\n0x7fffffff triggers:\\n\\n  UBSAN: array-index-out-of-bounds in kernel/cgroup/rstat.c:31:9\\n  index 2147483647 is out of range for type \u0027long unsigned int [64]\u0027\\n  Call Trace:\\n    css_rstat_updated\\n    bpf_iter_run_prog\\n    cgroup_iter_seq_show\\n    bpf_seq_read\\n\\nAdd cpu validation to the BPF-facing css_rstat_updated() kfunc and\\nmove the common implementation to __css_rstat_updated() for in-kernel\\ncallers.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"block/blk-cgroup.c\",\"include/linux/cgroup.h\",\"kernel/cgroup/rstat.c\",\"mm/memcontrol.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"a319185be9f5ad13c2a296d448ac52ffe45d194c\",\"lessThan\":\"6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"a319185be9f5ad13c2a296d448ac52ffe45d194c\",\"lessThan\":\"fd2bd9fa7700ddf28296486b2598cff2f80cc819\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"a319185be9f5ad13c2a296d448ac52ffe45d194c\",\"lessThan\":\"8817005efbdfdf5d4e4814cb5dc52b53d12917d7\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"block/blk-cgroup.c\",\"include/linux/cgroup.h\",\"kernel/cgroup/rstat.c\",\"mm/memcontrol.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.1\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.1\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.34\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.0.11\",\"lessThanOrEqual\":\"7.0.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/8817005efbdfdf5d4e4814cb5dc52b53d12917d7\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/fd2bd9fa7700ddf28296486b2598cff2f80cc819\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-07-21T06:22:52+00:00",
      "cve": "CVE-2026-64036",
      "id": "CVE-2026-64036",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:known_affected": "198",
      "product_status:known_not_affected": "76",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: cgroup/rstat: validate cpu before css_rstat_cpu() access",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64036.json",
      "version": "3"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.