{"cve":"CVE-2026-72192","nvd":{"published":"2026-08-15T06:21:37.663","modified":"2026-10-16T19:17:13.660","status":"Received","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":[],"references":["https://git.kernel.org/stable/c/0af83b8155cc848e9f5d2c36e20a70d024214649","https://git.kernel.org/stable/c/194b00c99ba971fa7cf6acd747a36032c6de54eb","https://git.kernel.org/stable/c/53c5f3b2da3774b41534728aba295c098c9efa19","https://git.kernel.org/stable/c/9b6926ac9c970ae0b2c2fe6289b16e9aa10b6a67","https://git.kernel.org/stable/c/aaa1f956c0fc41089a4a534da7df91552a08a47c"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:48:17.459049833+00:00"},"epss":{"cve":"CVE-2026-72192","score":0.00738,"percentile":0.54233,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}