{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9"
            },
            {
              "fixed": "41e53a773db6342ac9a689ee5ba635c31744c9f0"
            },
            {
              "fixed": "8d5729350b236896f51379588d9a690b7fafb8db"
            },
            {
              "fixed": "e1955a94b6f17f4b058afa955a6f187eb3ed7615"
            },
            {
              "fixed": "5e7b8f3c539d69b2ed5f2408e2f75e68ce7eef43"
            },
            {
              "fixed": "ef7902be3f215b6bf7babe4dc9dd9a7d57dad7a7"
            },
            {
              "fixed": "299f962c0b02d048fb45d248b4da493d03f3175d"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.15.0"
            },
            {
              "fixed": "6.1.175"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.136"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.84"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.25"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31704.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: use check_add_overflow() to prevent u16 DACL size overflow\n\nset_posix_acl_entries_dacl() and set_ntacl_dacl() accumulate ACE sizes\nin u16 variables. When a file has many POSIX ACL entries, the\naccumulated size can wrap past 65535, causing the pointer arithmetic\n(char *)pndace + *size to land within already-written ACEs. Subsequent\nwrites then overwrite earlier entries, and pndacl-\u003esize gets a\ntruncated value.\n\nUse check_add_overflow() at each accumulation point to detect the\nwrap before it corrupts the buffer, consistent with existing\ncheck_mul_overflow() usage elsewhere in smbacl.c.",
  "id": "CVE-2026-31704",
  "modified": "2026-07-08T05:36:55.463900100Z",
  "published": "2026-05-01T13:56:03.243Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/299f962c0b02d048fb45d248b4da493d03f3175d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/41e53a773db6342ac9a689ee5ba635c31744c9f0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5e7b8f3c539d69b2ed5f2408e2f75e68ce7eef43"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8d5729350b236896f51379588d9a690b7fafb8db"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e1955a94b6f17f4b058afa955a6f187eb3ed7615"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ef7902be3f215b6bf7babe4dc9dd9a7d57dad7a7"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31704.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31704"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "summary": "ksmbd: use check_add_overflow() to prevent u16 DACL size overflow"
}