{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "6ce19aff0b8cd386860855185c6cd79337fc4d2b"
            },
            {
              "fixed": "fcc051d377a9701a452e7663a1a8223c26225df9"
            },
            {
              "fixed": "29115b8c9172d34e67ab26cc4f6c209b7a236d7a"
            },
            {
              "fixed": "13e4b59d3a9413f66f116fa6c4828519b960a5ea"
            },
            {
              "fixed": "16161444c30d8dff9428abbae42b72ce4e32a932"
            },
            {
              "fixed": "77f216ff9ce5cde8eed9f6d12707e906dffdc9f7"
            },
            {
              "fixed": "0969926d987bbde9a1aa49da317582ba37095805"
            },
            {
              "fixed": "5073c66a96a9c23c0c2533ed4ed06e42f9021208"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "a23706426da9b611be5beae0f3faa260fb453b4e"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "5.13.19"
            },
            {
              "fixed": "5.14"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.14.0"
            },
            {
              "fixed": "5.15.212"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.177"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.144"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.95"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.38"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63817.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: validate compress cache inode only when enabled\n\nF2FS_COMPRESS_INO() uses NM_I(sbi)-\u003emax_nid as the synthetic inode\nnumber for the compressed page cache inode. That inode only exists when\nthe compress_cache mount option is enabled.\n\nWhen compress_cache is disabled, max_nid is outside the valid inode\nrange. A corrupted directory entry that points to ino == max_nid should\ntherefore be rejected by f2fs_check_nid_range(). However, is_meta_ino()\ncurrently treats F2FS_COMPRESS_INO() as a meta inode unconditionally,\nso f2fs_iget() bypasses do_read_inode() and its nid range check, and\ninstantiates a fake internal inode instead.\n\nGate the compressed cache inode case on COMPRESS_CACHE, matching\nf2fs_init_compress_inode(). With compress_cache disabled, ino ==\nmax_nid now follows the normal inode path and is rejected as an\nout-of-range nid.",
  "id": "CVE-2026-63817",
  "modified": "2026-08-18T03:30:59.314656300Z",
  "published": "2026-07-19T12:02:16.441Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0969926d987bbde9a1aa49da317582ba37095805"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/13e4b59d3a9413f66f116fa6c4828519b960a5ea"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/16161444c30d8dff9428abbae42b72ce4e32a932"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/29115b8c9172d34e67ab26cc4f6c209b7a236d7a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5073c66a96a9c23c0c2533ed4ed06e42f9021208"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/77f216ff9ce5cde8eed9f6d12707e906dffdc9f7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fcc051d377a9701a452e7663a1a8223c26225df9"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63817.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63817"
    },
    {
      "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:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "f2fs: validate compress cache inode only when enabled"
}