{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64323", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.780Z", "datePublished": "2026-07-25T08:49:51.097Z", "dateUpdated": "2026-08-17T04:53:25.005Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:53:25.005Z" }, "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." } ], "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." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/udf/super.c" ], "versions": [ { "version": "fa5e08156335d0687c85b4e724db9448fb166601", "lessThan": "0ad2d09a8d66fa8dc6f9b70d660b5fb4478ea934", "status": "affected", "versionType": "git" }, { "version": "fa5e08156335d0687c85b4e724db9448fb166601", "lessThan": "883962731420ec271ed8c1cd76524f4b17faa982", "status": "affected", "versionType": "git" }, { "version": "fa5e08156335d0687c85b4e724db9448fb166601", "lessThan": "2900e02a0dd4fc30ac9840e7ce4ca0b041ab0d63", "status": "affected", "versionType": "git" }, { "version": "fa5e08156335d0687c85b4e724db9448fb166601", "lessThan": "bb0d384c1f42a5b7ace0bd88fee80b9bb1d49acb", "status": "affected", "versionType": "git" }, { "version": "fa5e08156335d0687c85b4e724db9448fb166601", "lessThan": "55287a3555ff0515b3aff181d2c08c0462a41709", "status": "affected", "versionType": "git" }, { "version": "fa5e08156335d0687c85b4e724db9448fb166601", "lessThan": "e610fb113cdfa8bf4247c9bf4f2337b81ad4ddad", "status": "affected", "versionType": "git" }, { "version": "fa5e08156335d0687c85b4e724db9448fb166601", "lessThan": "74580fdf022909e184223cacc364feb826982d96", "status": "affected", "versionType": "git" }, { "version": "fa5e08156335d0687c85b4e724db9448fb166601", "lessThan": "d8202786b3d75125c84ebc4de6d946f92fde0ee8", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/udf/super.c" ], "versions": [ { "version": "2.6.26", "status": "affected" }, { "version": "0", "lessThan": "2.6.26", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.261", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.96", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "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" } ] } ] } ], "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" } } } }