{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "9b9960a0ca4773e21c4b153ed355583946346b25"
            },
            {
              "fixed": "e7d9d23ecd9172f05b09bb678ff22db8e361c428"
            },
            {
              "fixed": "0380129b1373c437eb35401a174671c8888f4b80"
            },
            {
              "fixed": "c81cef6a805dec266c10fc4f83c93d6fcf1a2b43"
            },
            {
              "fixed": "f9868174af49d207fbaf0c5e055d088a983684af"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.8.0"
            },
            {
              "fixed": "6.12.109"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.50"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89674.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix XDR length calculation in nfsd4_ff_encode_layoutget\n\nThe XDR buffer size calculation in nfsd4_ff_encode_layoutget() has\nmultiple errors that can result in either an out-of-bounds write or\nleaking uninitialized kernel memory to the client:\n\n - fh_len doesn't account for XDR padding on the file handle data\n - uid and gid lengths use \"8 + len\" but xdr_encode_opaque() actually\n   writes \"4 + xdr_align_size(len)\" bytes\n - ds_len omits the flags and stats_collect_hint fields (8 bytes),\n   while len's header constant overestimates by 8 bytes -- these\n   partially cancel but leave a net mismatch\n\nThe worst case occurs with short strings (e.g. uid=0, gid=0 with an\nodd-sized file handle), where the function writes up to 5 bytes past\nthe reserved XDR buffer. Conversely, when string lengths happen to be\n4-byte aligned, the reservation is too large and stale buffer content\nis sent to the client.\n\nFix this by breaking out every encoded field explicitly in the ds_len\ncalculation, using xdr_align_size() for all variable-length opaque\nfields, and correcting the header constants.",
  "id": "CVE-2026-89674",
  "modified": "2026-09-13T03:30:51.810210759Z",
  "published": "2026-09-11T19:45:58.883Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0380129b1373c437eb35401a174671c8888f4b80"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c81cef6a805dec266c10fc4f83c93d6fcf1a2b43"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e7d9d23ecd9172f05b09bb678ff22db8e361c428"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f9868174af49d207fbaf0c5e055d088a983684af"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89674.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89674"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "nfsd: fix XDR length calculation in nfsd4_ff_encode_layoutget"
}