{"id":"CVE-2026-64322","title":"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->reallocatio…","summary":"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->reallocatio…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","published":"2026-07-25","updated":"2026-07-27","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64322","references":[{"url":"https://git.kernel.org/stable/c/04f4599a9efb90992d072a814960edf0cd62805d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/0a9b79a951cfd70a9d31ca01ae2d08a20bb730e9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2a219acb2ce674d99bbd1b7b35ed8c384dac7200","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2d726135099313958f8975532a2e15322ff150ce","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3ec997bd5508e9b25210b5bbec89031629cdb093","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7285276aa50d2839afb5957ffd491ad282dc8f72","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7f7774b9da0ef17b87bfa238cf966ad0b3376150","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/eeb0f3e193f8e523d03e4c9e084f6b4875f50e8e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.00169,"epssPercentile":0.06263,"ingestedAt":"2026-07-27T06:16:50.529Z","vendor":"Linux","product":"Linux","affected":["Linux >= 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 < eeb0f3e193f8e523d03e4c9e084f6b4875f50e8e","Linux >= 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 < 0a9b79a951cfd70a9d31ca01ae2d08a20bb730e9","Linux >= 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 < 2d726135099313958f8975532a2e15322ff150ce","Linux >= 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 < 7285276aa50d2839afb5957ffd491ad282dc8f72","Linux >= 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 < 2a219acb2ce674d99bbd1b7b35ed8c384dac7200","Linux >= 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 < 04f4599a9efb90992d072a814960edf0cd62805d","Linux >= 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 < 7f7774b9da0ef17b87bfa238cf966ad0b3376150","Linux >= 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 < 3ec997bd5508e9b25210b5bbec89031629cdb093","Linux e240873cb4a9fd18de60a817100a96fe670d4359","Linux 9ae30e324a96d0328a575329d7a95a09b3318601","Linux b1c5701ad6b3e5d21d16f65475651cfaaa41e7aa","Linux a9f1af04f086656246f30354fb4564ce3b08c4a0","Linux 4836ee563d65bb492f907cbe267a5761b9693e4d","Linux >= 2.6.32.60 < 2.6.33","Linux >= 2.6.34.14 < 2.6.35","Linux >= 3.0.37 < 3.1","Linux >= 3.2.23 < 3.3","Linux >= 3.4.5 < 3.5","Linux 3.5"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:39:07.495740Z"},"slug":"CVE-2026-64322","body":"## Overview\n\nIn 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().\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}