ethtool: cmis: validate start_cmd_payload_size from module

{
  "id": "0a3e53fbd461c71ec52049997642b00ed086a758c500bce910e712d7732f8a2e",
  "url": "https://osv.dev/vulnerability/CVE-2026-63995",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ethtool: cmis: validate start_cmd_payload_size from module",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ethtool: cmis: validate start_cmd_payload_size from module The CMIS firmware update code reads start_cmd_payload_size from the module's FW Management Features CDB reply and uses it directly as the byte count for memcpy. The destination buffer is 112 bytes (ETHTOOL_CMIS_CDB_LPL_MAX_PL_LENGTH - 8). So a malicious module (or corrupted response) can cause a OOB write later on in cmis_fw_update_start_download(). Let's error out. If modules that expect longer LPL writes actually exist we should revisit. struct cmis_cdb_start_fw_download_pl's definition has to move, no change there.",
    "evidence": "osv:CVE-2026-63995",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.93",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.35",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.12",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-63995",
      "aliases": [
        "CVE-2026-63995"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "c4f78134d45c9619339c96b4bea380b1d0699788"
                },
                {
                  "fixed": "63112b4515469d00008452d9cfe3fb3bf1aa2df3"
                },
                {
                  "fixed": "0696709e951be54c699664adf546d16e28974d53"
                },
                {
                  "fixed": "a46340da00385be7fb16c62425ebc20006f2d5d8"
                },
                {
                  "fixed": "12c2496a71f82f63617971ca9b730dffa05cf58b"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63995.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.11.0"
                },
                {
                  "fixed": "6.12.93"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.35"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.0.12"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-63995.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.745832827Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0696709e951be54c699664adf546d16e28974d53",
        "https://git.kernel.org/stable/c/12c2496a71f82f63617971ca9b730dffa05cf58b",
        "https://git.kernel.org/stable/c/63112b4515469d00008452d9cfe3fb3bf1aa2df3",
        "https://git.kernel.org/stable/c/a46340da00385be7fb16c62425ebc20006f2d5d8",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63995.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-63995",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63995.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-63995",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 490256,
  "published_at": "2026-07-19T14:56:14.58+00:00"
}