{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72192","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-09T03:40:39.911Z","datePublished":"2026-08-15T05:53:52.634Z","dateUpdated":"2026-08-17T05:41:19.697Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T05:41:19.697Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nntfs3: bound to_move in indx_insert_into_root before hdr_insert_head\n\nindx_insert_into_root() promotes a full resident $INDEX_ROOT into\n$INDEX_ALLOCATION and copies all non-last resident root entries into\na newly allocated INDEX_BUFFER via hdr_insert_head(). The source\nbyte count 'to_move' is summed from the on-disk resident entry sizes\nand is independent of the destination buffer size, which comes from\nroot->index_block_size (via indx->index_bits).\n\nA crafted NTFS image that keeps a valid, full resident root but\nshrinks root->index_block_size down to 512 after the root has been\npopulated makes hdr_insert_head() memcpy attacker-controlled resident\nentry bytes past the end of the kmalloc(1u << indx->index_bits)\nallocation returned by indx_new(). For a 512-byte destination and a\nresident root whose non-last entries total 560 bytes, the memcpy\noverruns by 120 bytes and a following memmove extends the highest\nwritten offset to 136 bytes past the allocation. The overflow bytes\nare a direct copy of on-disk entries (via kmemdup), so they are\nfully attacker-controlled.\n\nThe write is reachable from unprivileged open(O_CREAT) on a mounted\ncrafted NTFS image: a single sufficiently long create in a directory\nwhose resident root is already full forces root promotion and\ntriggers the copy.\n\nThis is a controlled out-of-bounds write of 120-136 bytes past a\nkmalloc(index_block_size) allocation, with attacker-controlled\ncontent. It is a bounded adjacent-heap corruption primitive; it is\nnot an arbitrary-address write. Successful exploitation into a named\nvictim object depends on the surrounding slab layout.\n\nReject the copy at the sink. The destination's INDEX_HDR already\nreports hdr_total (the payload capacity of the new buffer) and\nhdr_used (the bytes already consumed by the terminal END entry\ninstalled by indx_new()); require that to_move fits in the remaining\npayload before calling hdr_insert_head(). On mismatch, fail with\n-EINVAL and mark the filesystem as having a detected on-disk\ninconsistency, which is the same behaviour as the surrounding\nvalidation in this function."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - ntfs3 registers export_operations; on NAS/hybrid servers exporting an NTFS volume via nfsd or ksmbd, a remote client's CREATE reaches vfs_create→ntfs_create→ntfs_create_inode→indx_insert_entry→indx_insert_into_root without any local syscall from the attacker.\nAC:L - The attacker fully controls on-disk $INDEX_ROOT layout (resident entry sizes and index_block_size); a single create in a full resident directory deterministically forces root promotion and the unchecked hdr_insert_head() copy, with no races or victim-specific heap layout required to trigger the overflow.\nPR:N - Exploitation needs only write access to create a file in the target directory on an NFS/SMB-exported NTFS share (including guest/anonymous write), or supplying removable media later mounted by the host; no init-namespace root or CAP_SYS_ADMIN is required on the trigger path.\nUI:N - Once an administrator has mounted and optionally exported the NTFS volume—or desktop/kiosk automount has attached removable media—the attacker issues open(O_CREAT)/touch/mkdir directly; no further victim clicks, file opens, or cooperative actions beyond that standing configuration are required.\nS:U - Impact is attacker-controlled kernel heap corruption and panic within the host kernel's security authority; this is standard local or network filesystem exploitation, not a VM escape, IOMMU bypass, or cross-scope sandbox breakout.\nC:H - hdr_insert_head() memcpy/memmove writes 120-136 attacker-controlled bytes past the kzalloc(1u<