CVE-2026-89792 (GCVE-0-2026-89792)
Vulnerability from cvelistv5
Published
2026-09-16 08:50
Modified
2026-10-19 08:52
Severity ?
7.1 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: prevent out-of-bounds reads in share config responses Validate IPC share configuration payload sizes before consuming variable-length fields. Bound veto list parsing and account for the separator byte when deriving the path length.
References
Impacted products
Vendor Product Version
Linux Linux Version: 88b7f1143b15b29cccb8392b4f38e75b7bb3e300
Version: 51a6c2af9d20203ddeeaf73314ba8854b38d01bd
Version: a637fabac554270a851033f5ab402ecb90bc479c
Version: a677ebd8ca2f2632ccdecbad7b87641274e15aac
Version: a677ebd8ca2f2632ccdecbad7b87641274e15aac
Version: a677ebd8ca2f2632ccdecbad7b87641274e15aac
Version: a677ebd8ca2f2632ccdecbad7b87641274e15aac
Version: 76af689a45aa44714b46d1a7de4ffdf851ded896
Version: 5.15.157   ≤
Version: 6.1.85   ≤
Version: 6.6.26   ≤
Version: 6.8.5   ≤
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/mgmt/share_config.c",
            "fs/smb/server/transport_ipc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "df8aa4a09733c4d3974b1db32c1782b3aad3a151",
              "status": "affected",
              "version": "88b7f1143b15b29cccb8392b4f38e75b7bb3e300",
              "versionType": "git"
            },
            {
              "lessThan": "0127f1c119bde40578f4d25f5d17333b4e75de8c",
              "status": "affected",
              "version": "51a6c2af9d20203ddeeaf73314ba8854b38d01bd",
              "versionType": "git"
            },
            {
              "lessThan": "fd636a87161def6e35876ab7943641ce457974c8",
              "status": "affected",
              "version": "a637fabac554270a851033f5ab402ecb90bc479c",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "a677ebd8ca2f2632ccdecbad7b87641274e15aac",
              "versionType": "git"
            },
            {
              "lessThan": "cd2bcee450bc94770be56c0b896c1a1dc6838bd8",
              "status": "affected",
              "version": "a677ebd8ca2f2632ccdecbad7b87641274e15aac",
              "versionType": "git"
            },
            {
              "lessThan": "61a8d06600c8c397f9a7e01940479d4c94a82f5f",
              "status": "affected",
              "version": "a677ebd8ca2f2632ccdecbad7b87641274e15aac",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "a677ebd8ca2f2632ccdecbad7b87641274e15aac",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "76af689a45aa44714b46d1a7de4ffdf851ded896",
              "versionType": "git"
            },
            {
              "lessThan": "5.15.222",
              "status": "affected",
              "version": "5.15.157",
              "versionType": "semver"
            },
            {
              "lessThan": "6.1.189",
              "status": "affected",
              "version": "6.1.85",
              "versionType": "semver"
            },
            {
              "lessThan": "6.6.158",
              "status": "affected",
              "version": "6.6.26",
              "versionType": "semver"
            },
            {
              "lessThan": "6.9",
              "status": "affected",
              "version": "6.8.5",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/mgmt/share_config.c",
            "fs/smb/server/transport_ipc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.9"
            },
            {
              "lessThan": "6.9",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.222",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.189",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.158",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.222",
                  "versionStartIncluding": "5.15.157",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.189",
                  "versionStartIncluding": "6.1.85",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.158",
                  "versionStartIncluding": "6.6.26",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.111",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.53",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "6.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.8.5",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: prevent out-of-bounds reads in share config responses\n\nValidate IPC share configuration payload sizes before consuming\nvariable-length fields. Bound veto list parsing and account for\nthe separator byte when deriving the path length."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - Malformed payload_sz/veto_list_sz and unterminated veto/path bytes are consumed from a ksmbd generic-netlink SHARE_CONFIG_RESPONSE (handle_generic_event \u2192 ipc_validate_msg \u2192 share_config_request), not from SMB PDUs. A remote TREE_CONNECT only creates the pending IPC request; the attacker must be local to inject or control that response.\nAC:L - The attacker fully controls the crafted netlink length fields and can set payload_sz to 0 or omit NULs so the old checks pass. Pending handles come from a small IDA and can be brute-forced against a TREE_CONNECT the attacker also triggers; no victim timing or rare config is required.\nPR:L - handle_generic_event requires CAP_NET_ADMIN only when CONFIG_SMB_SERVER_CHECK_CAP_NET_ADMIN is set; SMBD_GENL is netns-aware, has no GENL_ADMIN_PERM, and does not bind responses to ksmbd_tools_pid. That capability is Low, and builds that disable the check allow any local user to send the message.\nUI:N - The attacker sends the malformed SHARE_CONFIG_RESPONSE and can issue the matching SMB2 TREE_CONNECT themselves; no separate victim or administrator action is required once ksmbd is running.\nS:U - The out-of-bounds reads and any resulting oops remain inside the ksmbd/kernel security authority on the host. This is not a VM escape, IOMMU/DMA bypass, or other cross-boundary impact.\nC:H - With payload_sz==0 the kernel kstrndup()s up to PATH_MAX bytes past the IPC object, and parse_veto_list() uses unbounded strlen()/kstrdup() when the veto buffer lacks a NUL within veto_list_sz. Those are large kernel-heap over-reads, not a few bounded bytes.\nI:N - The defects are out-of-bounds reads (strlen, kstrndup, kstrdup) into newly allocated strings; there is no out-of-bounds write or control-flow hijack primitive. A local IPC sender can already supply a well-formed share path without this bug.\nA:H - Walking strlen() or kstrndup(..., PATH_MAX) off the end of the IPC slab into unmapped memory oopses the ksmbd worker. The attacker can repeat the crafted response against further TREE_CONNECT-triggered requests and crash the kernel at will."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T08:52:47.159Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/df8aa4a09733c4d3974b1db32c1782b3aad3a151"
        },
        {
          "url": "https://git.kernel.org/stable/c/0127f1c119bde40578f4d25f5d17333b4e75de8c"
        },
        {
          "url": "https://git.kernel.org/stable/c/fd636a87161def6e35876ab7943641ce457974c8"
        },
        {
          "url": "https://git.kernel.org/stable/c/ffa507f5f774cb4d45136b106989ebc051361263"
        },
        {
          "url": "https://git.kernel.org/stable/c/cd2bcee450bc94770be56c0b896c1a1dc6838bd8"
        },
        {
          "url": "https://git.kernel.org/stable/c/61a8d06600c8c397f9a7e01940479d4c94a82f5f"
        },
        {
          "url": "https://git.kernel.org/stable/c/f25e93768fcc5d8287e50b1ec52a42e4c276df34"
        }
      ],
      "title": "ksmbd: prevent out-of-bounds reads in share config responses",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89792",
    "datePublished": "2026-09-16T08:50:06.516Z",
    "dateReserved": "2026-09-11T19:38:34.766Z",
    "dateUpdated": "2026-10-19T08:52:47.159Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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