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CVE-2026-68098

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: bound DACL dedup walk to copied ACEs set_ntacl_dacl() can stop copying ACEs before consuming the full input DACL when size accounting overflows. When that happens, num_aces reflects only the ACEs that were actually copied into the output DACL, but set_posix_acl_entries_dacl() still receives nt_num_aces and uses it to walk the existing ACE array during dedup. That makes the dedup walk scan past the copied ACE array and inspect buffer tail that does not contain valid ACEs. Split the two meanings currently carried by the NT ACE count. Pass the number of copied NT ACEs to bound the dedup walk, and preserve the original "input DACL had NT ACEs" state separately for the Everyone/default ACL fallback. This keeps the dedup walk aligned with the ACEs that are actually present in the rebuilt DACL.

Severity
HIGH
CVSS score
8.8 (v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-08-10 13:19:54.200000
Last modified
2026-10-30 13:19:39.380000
View original CVE JSON
{
  "id": "CVE-2026-68098",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-08-10T13:19:54.200",
  "lastModified": "2026-10-30T13:19:39.380",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: bound DACL dedup walk to copied ACEs\n\nset_ntacl_dacl() can stop copying ACEs before consuming the full input\nDACL when size accounting overflows.\n\nWhen that happens, num_aces reflects only the ACEs that were actually\ncopied into the output DACL, but set_posix_acl_entries_dacl() still\nreceives nt_num_aces and uses it to walk the existing ACE array during\ndedup.\n\nThat makes the dedup walk scan past the copied ACE array and inspect\nbuffer tail that does not contain valid ACEs.\n\nSplit the two meanings currently carried by the NT ACE count. Pass the\nnumber of copied NT ACEs to bound the dedup walk, and preserve the\noriginal \"input DACL had NT ACEs\" state separately for the\nEveryone/default ACL fallback.\n\nThis keeps the dedup walk aligned with the ACEs that are actually\npresent in the rebuilt DACL."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "fs/smb/server/smbacl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "lessThan": "05aa552bd69a96e090cbd45656e18cdc46524e20",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "lessThan": "6d9d7aa4a2c99c31acfa28921c30b684110cf66c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "lessThan": "b057a851129c6a084e7e393b62ca3abf6c2660bc",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "lessThan": "f1eba60db813ec28732bf18b5f0a67ebac9c3100",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "lessThan": "a0ebdaa79e10210d4e8ed9fe138e8f4d569719e3",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
              "lessThan": "58d97fcd0bf1aee694e244cc28635b9df95b543b",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "fs/smb/server/smbacl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5.15",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "5.15",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.148",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.101",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.42",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.6",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "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:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-16T15:43:43.543991Z",
          "id": "CVE-2026-68098",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/05aa552bd69a96e090cbd45656e18cdc46524e20",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/58d97fcd0bf1aee694e244cc28635b9df95b543b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6d9d7aa4a2c99c31acfa28921c30b684110cf66c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a0ebdaa79e10210d4e8ed9fe138e8f4d569719e3",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b057a851129c6a084e7e393b62ca3abf6c2660bc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f1eba60db813ec28732bf18b5f0a67ebac9c3100",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}