{"api_version":"1","generated_at":"2026-08-02T14:53:18+00:00","cve":"CVE-2026-64323","urls":{"html":"https://cve.report/CVE-2026-64323","api":"https://cve.report/api/cve/CVE-2026-64323.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-64323","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64323"},"summary":{"title":"udf: validate VAT header length against the VAT inode size","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nudf: validate VAT header length against the VAT inode size\n\nudf_load_vat() takes the virtual partition's start offset straight from\nthe on-disk VAT 2.0 header without checking it against the VAT inode\nsize:\n\n\tmap->s_type_specific.s_virtual.s_start_offset =\n\t\tle16_to_cpu(vat20->lengthHeader);\n\tmap->s_type_specific.s_virtual.s_num_entries =\n\t\t(sbi->s_vat_inode->i_size -\n\t\t\tmap->s_type_specific.s_virtual.s_start_offset) >> 2;\n\nlengthHeader is a fully attacker-controlled 16-bit value.  If it exceeds\nthe VAT inode size, the s_num_entries subtraction underflows to a huge\ncount, which defeats the \"block > s_num_entries\" bound in\nudf_get_pblock_virt15(); and on the ICB-inline path that function reads\n\n\t((__le32 *)(iinfo->i_data + s_start_offset))[block]\n\nso a large s_start_offset indexes past the inode's in-ICB data.  Mounting\na crafted UDF image with a virtual (VAT) partition then triggers an\nout-of-bounds read.\n\nReject a VAT whose header length does not leave room for at least one\nentry within the VAT inode.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-25 10:17:13","updated_at":"2026-07-27 05:16:42"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.1","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","baseScore":7.1,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.1","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","data":{"baseScore":7.1,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/2900e02a0dd4fc30ac9840e7ce4ca0b041ab0d63","name":"https://git.kernel.org/stable/c/2900e02a0dd4fc30ac9840e7ce4ca0b041ab0d63","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/883962731420ec271ed8c1cd76524f4b17faa982","name":"https://git.kernel.org/stable/c/883962731420ec271ed8c1cd76524f4b17faa982","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d8202786b3d75125c84ebc4de6d946f92fde0ee8","name":"https://git.kernel.org/stable/c/d8202786b3d75125c84ebc4de6d946f92fde0ee8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/74580fdf022909e184223cacc364feb826982d96","name":"https://git.kernel.org/stable/c/74580fdf022909e184223cacc364feb826982d96","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e610fb113cdfa8bf4247c9bf4f2337b81ad4ddad","name":"https://git.kernel.org/stable/c/e610fb113cdfa8bf4247c9bf4f2337b81ad4ddad","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/bb0d384c1f42a5b7ace0bd88fee80b9bb1d49acb","name":"https://git.kernel.org/stable/c/bb0d384c1f42a5b7ace0bd88fee80b9bb1d49acb","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/0ad2d09a8d66fa8dc6f9b70d660b5fb4478ea934","name":"https://git.kernel.org/stable/c/0ad2d09a8d66fa8dc6f9b70d660b5fb4478ea934","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/55287a3555ff0515b3aff181d2c08c0462a41709","name":"https://git.kernel.org/stable/c/55287a3555ff0515b3aff181d2c08c0462a41709","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64323","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64323","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected fa5e08156335d0687c85b4e724db9448fb166601 0ad2d09a8d66fa8dc6f9b70d660b5fb4478ea934 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected fa5e08156335d0687c85b4e724db9448fb166601 883962731420ec271ed8c1cd76524f4b17faa982 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected fa5e08156335d0687c85b4e724db9448fb166601 2900e02a0dd4fc30ac9840e7ce4ca0b041ab0d63 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected fa5e08156335d0687c85b4e724db9448fb166601 bb0d384c1f42a5b7ace0bd88fee80b9bb1d49acb git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"64323","cve":"CVE-2026-64323","epss":"0.001600000","percentile":"0.055770000","score_date":"2026-07-29","updated_at":"2026-07-30 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the Linux kernel, the following vulnerability has been resolved:\n\nudf: validate VAT header length against the VAT inode size\n\nudf_load_vat() takes the virtual partition's start offset straight from\nthe on-disk VAT 2.0 header without checking it against the VAT inode\nsize:\n\n\tmap->s_type_specific.s_virtual.s_start_offset =\n\t\tle16_to_cpu(vat20->lengthHeader);\n\tmap->s_type_specific.s_virtual.s_num_entries =\n\t\t(sbi->s_vat_inode->i_size -\n\t\t\tmap->s_type_specific.s_virtual.s_start_offset) >> 2;\n\nlengthHeader is a fully attacker-controlled 16-bit value.  If it exceeds\nthe VAT inode size, the s_num_entries subtraction underflows to a huge\ncount, which defeats the \"block > s_num_entries\" bound in\nudf_get_pblock_virt15(); and on the ICB-inline path that function reads\n\n\t((__le32 *)(iinfo->i_data + s_start_offset))[block]\n\nso a large s_start_offset indexes past the inode's in-ICB data.  Mounting\na crafted UDF image with a virtual (VAT) partition then triggers an\nout-of-bounds read.\n\nReject a VAT whose header length does not leave room for at least one\nentry within the VAT inode."}],"metrics":[{"cvssV3_1":{"baseScore":7.1,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-07-27T04:59:49.230Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/0ad2d09a8d66fa8dc6f9b70d660b5fb4478ea934"},{"url":"https://git.kernel.org/stable/c/883962731420ec271ed8c1cd76524f4b17faa982"},{"url":"https://git.kernel.org/stable/c/2900e02a0dd4fc30ac9840e7ce4ca0b041ab0d63"},{"url":"https://git.kernel.org/stable/c/bb0d384c1f42a5b7ace0bd88fee80b9bb1d49acb"},{"url":"https://git.kernel.org/stable/c/55287a3555ff0515b3aff181d2c08c0462a41709"},{"url":"https://git.kernel.org/stable/c/e610fb113cdfa8bf4247c9bf4f2337b81ad4ddad"},{"url":"https://git.kernel.org/stable/c/74580fdf022909e184223cacc364feb826982d96"},{"url":"https://git.kernel.org/stable/c/d8202786b3d75125c84ebc4de6d946f92fde0ee8"}],"title":"udf: validate VAT header length against the VAT inode size","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-64323","datePublished":"2026-07-25T08:49:51.097Z","dateReserved":"2026-07-19T15:36:31.780Z","dateUpdated":"2026-07-27T04:59:49.230Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-25 10:17:13","lastModifiedDate":"2026-07-27 05:16:42","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:N/A:H","baseScore":7.1,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.2}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"64323","Ordinal":"1","Title":"udf: validate VAT header length against the VAT inode size","CVE":"CVE-2026-64323","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"64323","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nudf: validate VAT header length against the VAT inode size\n\nudf_load_vat() takes the virtual partition's start offset straight from\nthe on-disk VAT 2.0 header without checking it against the VAT inode\nsize:\n\n\tmap->s_type_specific.s_virtual.s_start_offset =\n\t\tle16_to_cpu(vat20->lengthHeader);\n\tmap->s_type_specific.s_virtual.s_num_entries =\n\t\t(sbi->s_vat_inode->i_size -\n\t\t\tmap->s_type_specific.s_virtual.s_start_offset) >> 2;\n\nlengthHeader is a fully attacker-controlled 16-bit value.  If it exceeds\nthe VAT inode size, the s_num_entries subtraction underflows to a huge\ncount, which defeats the \"block > s_num_entries\" bound in\nudf_get_pblock_virt15(); and on the ICB-inline path that function reads\n\n\t((__le32 *)(iinfo->i_data + s_start_offset))[block]\n\nso a large s_start_offset indexes past the inode's in-ICB data.  Mounting\na crafted UDF image with a virtual (VAT) partition then triggers an\nout-of-bounds read.\n\nReject a VAT whose header length does not leave room for at least one\nentry within the VAT inode.","Type":"Description","Title":"udf: validate VAT header length against the VAT inode size"}]}}}