{"id":"CVE-2026-64323","state":"PUBLISHED","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.","publishedAt":"2026-07-25T08:49:51.097Z","updatedAt":"2026-10-19T20:38:24.010Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"0ad2d09a8d66fa8dc6f9b70d660b5fb4478ea934","versionType":"git"},{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"883962731420ec271ed8c1cd76524f4b17faa982","versionType":"git"},{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"2900e02a0dd4fc30ac9840e7ce4ca0b041ab0d63","versionType":"git"},{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"bb0d384c1f42a5b7ace0bd88fee80b9bb1d49acb","versionType":"git"},{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"55287a3555ff0515b3aff181d2c08c0462a41709","versionType":"git"},{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"e610fb113cdfa8bf4247c9bf4f2337b81ad4ddad","versionType":"git"},{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"74580fdf022909e184223cacc364feb826982d96","versionType":"git"},{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"d8202786b3d75125c84ebc4de6d946f92fde0ee8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/udf/super.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.26","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.26","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/udf/super.c"]}],"references":["https://git.kernel.org/stable/c/0ad2d09a8d66fa8dc6f9b70d660b5fb4478ea934","https://git.kernel.org/stable/c/883962731420ec271ed8c1cd76524f4b17faa982","https://git.kernel.org/stable/c/2900e02a0dd4fc30ac9840e7ce4ca0b041ab0d63","https://git.kernel.org/stable/c/bb0d384c1f42a5b7ace0bd88fee80b9bb1d49acb","https://git.kernel.org/stable/c/55287a3555ff0515b3aff181d2c08c0462a41709","https://git.kernel.org/stable/c/e610fb113cdfa8bf4247c9bf4f2337b81ad4ddad","https://git.kernel.org/stable/c/74580fdf022909e184223cacc364feb826982d96","https://git.kernel.org/stable/c/d8202786b3d75125c84ebc4de6d946f92fde0ee8"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64323.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64323","state":"PUBLISHED","datePublished":"2026-07-25T08:49:51.097Z","dateUpdated":"2026-10-19T20:38:24.010Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.780Z"},"containers":{"cna":{"title":"udf: validate VAT header length against the VAT inode size","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"0ad2d09a8d66fa8dc6f9b70d660b5fb4478ea934","versionType":"git"},{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"883962731420ec271ed8c1cd76524f4b17faa982","versionType":"git"},{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"2900e02a0dd4fc30ac9840e7ce4ca0b041ab0d63","versionType":"git"},{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"bb0d384c1f42a5b7ace0bd88fee80b9bb1d49acb","versionType":"git"},{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"55287a3555ff0515b3aff181d2c08c0462a41709","versionType":"git"},{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"e610fb113cdfa8bf4247c9bf4f2337b81ad4ddad","versionType":"git"},{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"74580fdf022909e184223cacc364feb826982d96","versionType":"git"},{"version":"fa5e08156335d0687c85b4e724db9448fb166601","status":"affected","lessThan":"d8202786b3d75125c84ebc4de6d946f92fde0ee8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/udf/super.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.26","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.26","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/udf/super.c"]}],"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"}],"metrics":[{"cvssV3_1":{"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"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable parser is reached by mounting a crafted local UDF image or removable volume; no network-facing protocol reaches it.\nAC:L - The VAT type, inline allocation, header length, and virtual block index are attacker-controlled on disk, with no race or uncontrollable condition required.\nPR:L - Although direct mounting requires init-namespace CAP_SYS_ADMIN, common UDisks/polkit deployments let an active unprivileged local user create a loop device and request the mount.\nUI:N - In the low-privilege UDisks scenario, the attacker can initiate the mount and trigger VAT resolution without another user's action.\nS:U - The vulnerable UDF parser and affected kernel resources remain within the host kernel's security authority.\nC:H - The underflow permits repeatable 32-bit reads at attacker-selected offsets potentially many gigabytes beyond the VAT buffer, enabling disclosure of kernel memory.\nI:N - The primitive only reads a mapping value, and virtual UDF partitions are forcibly read-only; no kernel-memory write primitive results.\nA:H - A sufficiently large attacker-selected index can fault in kernel context and cause an oops or panic, enabling repeatable system-wide denial of service."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:53:25.005Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"5.10.261"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"5.15.212"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"6.12.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64323","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:39:09.958903Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","type":"CWE","description":"CWE-125 Out-of-bounds Read"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:38:24.010Z"}}]}}}