{"api_version":"1","generated_at":"2026-07-24T19:14:20+00:00","cve":"CVE-2026-63817","urls":{"html":"https://cve.report/CVE-2026-63817","api":"https://cve.report/api/cve/CVE-2026-63817.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-63817","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-63817"},"summary":{"title":"f2fs: validate compress cache inode only when enabled","description":"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)->max_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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-19 12:16:54","updated_at":"2026-07-24 15:19:04"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/0969926d987bbde9a1aa49da317582ba37095805","name":"https://git.kernel.org/stable/c/0969926d987bbde9a1aa49da317582ba37095805","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/16161444c30d8dff9428abbae42b72ce4e32a932","name":"https://git.kernel.org/stable/c/16161444c30d8dff9428abbae42b72ce4e32a932","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/77f216ff9ce5cde8eed9f6d12707e906dffdc9f7","name":"https://git.kernel.org/stable/c/77f216ff9ce5cde8eed9f6d12707e906dffdc9f7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/13e4b59d3a9413f66f116fa6c4828519b960a5ea","name":"https://git.kernel.org/stable/c/13e4b59d3a9413f66f116fa6c4828519b960a5ea","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5073c66a96a9c23c0c2533ed4ed06e42f9021208","name":"https://git.kernel.org/stable/c/5073c66a96a9c23c0c2533ed4ed06e42f9021208","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/29115b8c9172d34e67ab26cc4f6c209b7a236d7a","name":"https://git.kernel.org/stable/c/29115b8c9172d34e67ab26cc4f6c209b7a236d7a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/fcc051d377a9701a452e7663a1a8223c26225df9","name":"https://git.kernel.org/stable/c/fcc051d377a9701a452e7663a1a8223c26225df9","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63817","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63817","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6ce19aff0b8cd386860855185c6cd79337fc4d2b fcc051d377a9701a452e7663a1a8223c26225df9 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6ce19aff0b8cd386860855185c6cd79337fc4d2b 29115b8c9172d34e67ab26cc4f6c209b7a236d7a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6ce19aff0b8cd386860855185c6cd79337fc4d2b 13e4b59d3a9413f66f116fa6c4828519b960a5ea git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6ce19aff0b8cd386860855185c6cd79337fc4d2b 16161444c30d8dff9428abbae42b72ce4e32a932 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.177 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.144 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.95 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.38 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.3 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"63817","cve":"CVE-2026-63817","epss":"0.001690000","percentile":"0.065840000","score_date":"2026-07-20","updated_at":"2026-07-21 00:13:14"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/f2fs/inode.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"fcc051d377a9701a452e7663a1a8223c26225df9","status":"affected","version":"6ce19aff0b8cd386860855185c6cd79337fc4d2b","versionType":"git"},{"lessThan":"29115b8c9172d34e67ab26cc4f6c209b7a236d7a","status":"affected","version":"6ce19aff0b8cd386860855185c6cd79337fc4d2b","versionType":"git"},{"lessThan":"13e4b59d3a9413f66f116fa6c4828519b960a5ea","status":"affected","version":"6ce19aff0b8cd386860855185c6cd79337fc4d2b","versionType":"git"},{"lessThan":"16161444c30d8dff9428abbae42b72ce4e32a932","status":"affected","version":"6ce19aff0b8cd386860855185c6cd79337fc4d2b","versionType":"git"},{"lessThan":"77f216ff9ce5cde8eed9f6d12707e906dffdc9f7","status":"affected","version":"6ce19aff0b8cd386860855185c6cd79337fc4d2b","versionType":"git"},{"lessThan":"0969926d987bbde9a1aa49da317582ba37095805","status":"affected","version":"6ce19aff0b8cd386860855185c6cd79337fc4d2b","versionType":"git"},{"lessThan":"5073c66a96a9c23c0c2533ed4ed06e42f9021208","status":"affected","version":"6ce19aff0b8cd386860855185c6cd79337fc4d2b","versionType":"git"},{"status":"affected","version":"a23706426da9b611be5beae0f3faa260fb453b4e","versionType":"git"},{"lessThan":"5.14","status":"affected","version":"5.13.19","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/f2fs/inode.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.14"},{"lessThan":"5.14","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.212","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.177","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.144","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.95","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.38","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.3","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.212","versionStartIncluding":"5.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.177","versionStartIncluding":"5.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.144","versionStartIncluding":"5.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.95","versionStartIncluding":"5.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.38","versionStartIncluding":"5.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.3","versionStartIncluding":"5.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc1","versionStartIncluding":"5.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13.19","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"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)->max_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."}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-07-24T14:34:10.308Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/fcc051d377a9701a452e7663a1a8223c26225df9"},{"url":"https://git.kernel.org/stable/c/29115b8c9172d34e67ab26cc4f6c209b7a236d7a"},{"url":"https://git.kernel.org/stable/c/13e4b59d3a9413f66f116fa6c4828519b960a5ea"},{"url":"https://git.kernel.org/stable/c/16161444c30d8dff9428abbae42b72ce4e32a932"},{"url":"https://git.kernel.org/stable/c/77f216ff9ce5cde8eed9f6d12707e906dffdc9f7"},{"url":"https://git.kernel.org/stable/c/0969926d987bbde9a1aa49da317582ba37095805"},{"url":"https://git.kernel.org/stable/c/5073c66a96a9c23c0c2533ed4ed06e42f9021208"}],"title":"f2fs: validate compress cache inode only when enabled","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-63817","datePublished":"2026-07-19T12:02:16.441Z","dateReserved":"2026-07-19T07:54:57.014Z","dateUpdated":"2026-07-24T14:34:10.308Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-19 12:16:54","lastModifiedDate":"2026-07-24 15:19:04","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"63817","Ordinal":"1","Title":"f2fs: validate compress cache inode only when enabled","CVE":"CVE-2026-63817","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"63817","Ordinal":"1","NoteData":"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)->max_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.","Type":"Description","Title":"f2fs: validate compress cache inode only when enabled"}]}}}