CVE Catalog

CVE-2026-64322

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.16%

6th percentile - higher than 6% of all known CVEs

Summary

In the Linux kernel, the UDF filesystem has a vulnerability due to incorrect validation of the sparing table length. The function treats reallocationTableLen as a byte count, while it is actually a count of 8-byte entries, leading to out-of-bounds memory access.

Risk Assessment

An attacker can exploit a crafted UDF image to perform out-of-bounds read or write, potentially leading to data leakage or system compromise.

Recommendation

Immediately update the Linux kernel to a version containing the fix that validates reallocationTableLen as an entry count.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: udf: validate sparing table length as an entry count, not a byte count udf_load_sparable_map() accepts a sparing table when sizeof(*st) + le16_to_cpu(st->reallocationTableLen) > sb->s_blocksize is false, i.e. it treats reallocationTableLen as a number of BYTES that must fit in the block. But the table is walked as an array of 8-byte sparingEntry elements: for (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) { struct sparingEntry *entry = &st->mapEntry[i]; ... entry->origLocation ... } in udf_get_pblock_spar15() and udf_relocate_blocks(). A reallocationTableLen of N therefore passes the check whenever sizeof(*st) + N <= blocksize, yet the consumers index sizeof(*st) + N * sizeof(struct sparingEntry) bytes -- up to ~8x the block. On a crafted UDF image this is an out-of-bounds read in udf_get_pblock_spar15(); udf_relocate_blocks() additionally feeds the same length to udf_update_tag(), whose crc_itu_t() reads far past the block, and its memmove() through st->mapEntry[] is an out-of-bounds write. Validate reallocationTableLen as the entry count it is, with struct_size().

Vulnerability data from NVD (NIST) · CISA KEV · EPSS