CVE-2026-64323High· 7.1▾ TwilightIn the Linux kernel, the following vulnerability has been resolved: udf: validate VAT header length against the VAT inode size udf_load_vat() takes the virtual partition's start offset straight from the on-disk VAT 2.0 header without c…
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 39.1 · likelihood 0 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 27.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
Last analysed / modified upstream
0.2%
0.2% → 0.2%
In the Linux kernel, the following vulnerability has been resolved:
udf: validate VAT header length against the VAT inode size
udf_load_vat() takes the virtual partition's start offset straight from the on-disk VAT 2.0 header without checking it against the VAT inode size:
map->s_type_specific.s_virtual.s_start_offset =
le16_to_cpu(vat20->lengthHeader);
map->s_type_specific.s_virtual.s_num_entries =
(sbi->s_vat_inode->i_size -
map->s_type_specific.s_virtual.s_start_offset) >> 2;
lengthHeader is a fully attacker-controlled 16-bit value. If it exceeds the VAT inode size, the s_num_entries subtraction underflows to a huge count, which defeats the "block > s_num_entries" bound in udf_get_pblock_virt15(); and on the ICB-inline path that function reads
((__le32 *)(iinfo->i_data + s_start_offset))[block]
so a large s_start_offset indexes past the inode's in-ICB data. Mounting a crafted UDF image with a virtual (VAT) partition then triggers an out-of-bounds read.
Reject a VAT whose header length does not leave room for at least one entry within the VAT inode.
Refer to the linked advisories for vendor-supplied fixes and affected version ranges.