{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2"
            },
            {
              "fixed": "b3bcd5d65ac03c15787b2a5b36c718e26a689336"
            },
            {
              "fixed": "35f258fee9ed358c6d0f57f91c30bf029c3724af"
            },
            {
              "fixed": "6eb6af88710977eb529b558a07294874d8c40c4d"
            },
            {
              "fixed": "9f77c1ab382188f5b51982fab6d913443b6dc59f"
            },
            {
              "fixed": "2c5988c7349c0b64a7e0441bfc6e1dca54f7116a"
            },
            {
              "fixed": "d0c80dbb970439bd2eeb0e5effff8c16a5f4e1e3"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.12"
            },
            {
              "fixed": "6.1.183"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.152"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.104"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.45"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74689.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/atm: fix slab-out-of-bounds read in vcc_setsockopt()\n\nvcc_setsockopt() contained an ineffective optlen check:\n  if (__SO_LEVEL_MATCH(optname, level) \u0026\u0026 optlen != __SO_SIZE(optname))\n      return -EINVAL;\n\nIf __SO_LEVEL_MATCH(optname, level) evaluated to false (e.g. if the caller\npassed a mismatched level), the length check optlen != __SO_SIZE(optname)\nwas short-circuited and bypassed. Execution then fell through to switch(optname),\ncalling copy_from_sockptr() assuming optval contained sufficient space.\n\nFurthermore, even if level matched, a cgroup BPF setsockopt filter could shrink\noptlen after entry. Because copy_from_sockptr() on kernel pointers uses memcpy(),\nthis leads to a KASAN slab-out-of-bounds read when optlen is smaller than the\nexpected structure size.\n\nFix this by using copy_safe_from_sockptr(), which unconditionally validates\nthat optlen is at least the expected size before copying. Also change the local\n'value' variable type from 'unsigned long' to 'int' so that SO_SETCLP matches\nits sizeof(int) ABI encoding on 64-bit systems.",
  "id": "CVE-2026-74689",
  "modified": "2026-08-27T11:30:54.034289249Z",
  "published": "2026-08-22T15:32:54.034Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2c5988c7349c0b64a7e0441bfc6e1dca54f7116a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/35f258fee9ed358c6d0f57f91c30bf029c3724af"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6eb6af88710977eb529b558a07294874d8c40c4d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9f77c1ab382188f5b51982fab6d913443b6dc59f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b3bcd5d65ac03c15787b2a5b36c718e26a689336"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d0c80dbb970439bd2eeb0e5effff8c16a5f4e1e3"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74689.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74689"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "net/atm: fix slab-out-of-bounds read in vcc_setsockopt()"
}