{"cve":"CVE-2026-68478","nvd":{"published":"2026-08-15T06:20:47.573","modified":"2026-08-17T06:17:57.333","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmemstick: ms_block: reject a card that reports too many blocks\n\nmsb_ftl_initialize() computes the zone count from the card block count\nwith no bound:\n\n\tmsb->zone_count = msb->block_count / MS_BLOCKS_IN_ZONE;\n\t...\n\tfor (i = 0; i < msb->zone_count; i++)\n\t\tmsb->free_block_count[i] = MS_BLOCKS_IN_ZONE;\n\nmsb->block_count is a card value. msb_read_boot_blocks() reads\nnumber_of_blocks from the card boot page and byte swaps it.\nfree_block_count is a fixed int[MS_MAX_ZONES]. MS_MAX_ZONES is 16, so the\nvalid indices are 0 to 15. The init loop above indexes it by zone_count.\nmsb_mark_block_used() and msb_mark_block_unused() index it by\npba / MS_BLOCKS_IN_ZONE, for pba up to block_count - 1. A card may report\nup to 65535 blocks. A block_count above 8192 (MS_MAX_ZONES *\nMS_BLOCKS_IN_ZONE) lets the pba index reach 16. That writes past\nfree_block_count[] and corrupts struct msb_data. A larger count runs the\ninit loop past the end too.\n\nA real Memory Stick has at most 16 zones. So it has at most 8192 blocks.\nmsb_ftl_initialize() now rejects a card that reports more than\nMS_MAX_ZONES * MS_BLOCKS_IN_ZONE blocks.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/39151f0708c84221e94cdd6aa070aba5d7cb1c01","https://git.kernel.org/stable/c/47f0c7d856c67c9935546d2644f18c0d0131b449","https://git.kernel.org/stable/c/718178f524b98bc920d74bc771aed823c8b81425","https://git.kernel.org/stable/c/8937b11f1c3896e066c3fb07387ba17bc8c50b8a","https://git.kernel.org/stable/c/a4b9961efe8640f50800811b4a2b2046b3dc2ccc"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:48:17.459049833+00:00"},"epss":{"cve":"CVE-2026-68478","score":0.0022,"percentile":0.12507,"date":"2026-11-01"},"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."]}