{"cve":"CVE-2026-89574","nvd":{"published":"2026-09-11T20:19:41.517","modified":"2026-10-21T13:20:09.273","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm array: validate array block headers on read\n\narray_block_check() validates blocknr and csum and nothing else, while\nnode_check(), next to it, has bounded the structural fields since both\nwere written. dm_array_cursor_next() takes its loop bound from the\non-disk nr_entries and element_at() is unguarded pointer arithmetic, so\na count larger than the block holds keeps the cursor in one block while\nthe index grows past it and the read walks off the dm-bufio buffer --\ndm_cache_load_mappings() drives it once per cache block at activation.\n\nCheck the header against itself: reject a zero value_size, require\nmax_entries to equal calc_max_entries() for that value_size and block\nsize, and require nr_entries to fit. Equality rather than an upper bound,\nsince a count below the real capacity trips BUG_ON() in fill_ablock() and\ntrim_ablock(). Metadata dm-array writes satisfies all three.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":[],"references":["https://git.kernel.org/stable/c/0e3b8f371c385c212b6e6f76c66f5b3f5bcfea62","https://git.kernel.org/stable/c/2965787723084835b18dfe993cd450ebf5bd4540","https://git.kernel.org/stable/c/67adda7ed5da3e3b64f5b9021a02c21fb374fd9c","https://git.kernel.org/stable/c/9808ddffb4bc659352df3020cd84d9d864820ee5","https://git.kernel.org/stable/c/b33f76d33aaeacf3baf3370d8d64985169b36600"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-89574","score":0.00168,"percentile":0.06171,"date":"2026-10-26"},"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."]}