{"cve":"CVE-2026-64322","nvd":{"published":"2026-07-25T10:17:13.640","modified":"2026-10-19T21:17:31.887","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nudf: validate sparing table length as an entry count, not a byte count\n\nudf_load_sparable_map() accepts a sparing table when\n\n\tsizeof(*st) + le16_to_cpu(st->reallocationTableLen) > sb->s_blocksize\n\nis false, i.e. it treats reallocationTableLen as a number of BYTES that\nmust fit in the block.  But the table is walked as an array of 8-byte\nsparingEntry elements:\n\n\tfor (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) {\n\t\tstruct sparingEntry *entry = &st->mapEntry[i];\n\t\t... entry->origLocation ...\n\t}\n\nin udf_get_pblock_spar15() and udf_relocate_blocks().  A\nreallocationTableLen of N therefore passes the check whenever\nsizeof(*st) + N <= blocksize, yet the consumers index\nsizeof(*st) + N * sizeof(struct sparingEntry) bytes -- up to ~8x the\nblock.  On a crafted UDF image this is an out-of-bounds read in\nudf_get_pblock_spar15(); udf_relocate_blocks() additionally feeds the\nsame length to udf_update_tag(), whose crc_itu_t() reads far past the\nblock, and its memmove() through st->mapEntry[] is an out-of-bounds\nwrite.\n\nValidate reallocationTableLen as the entry count it is, with\nstruct_size().","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":["CWE-787"],"references":["https://git.kernel.org/stable/c/04f4599a9efb90992d072a814960edf0cd62805d","https://git.kernel.org/stable/c/0a9b79a951cfd70a9d31ca01ae2d08a20bb730e9","https://git.kernel.org/stable/c/2a219acb2ce674d99bbd1b7b35ed8c384dac7200","https://git.kernel.org/stable/c/2d726135099313958f8975532a2e15322ff150ce","https://git.kernel.org/stable/c/3ec997bd5508e9b25210b5bbec89031629cdb093"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2026-64322","score":0.00169,"percentile":0.06259,"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."]}