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VulnerabilityPublished

CVE-2026-64323: Linux kernel · udf: validate VAT header length against the VAT inode size

Source GCVE Database

0
Authoritative record:CVE-2026-64323· High 7.1

Not known to be exploited · CVSS 7.1 High · fixed in e610fb113cdfa8bf4247c9bf4f2337b81ad4ddad : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
7.1High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in e610fb113cdfa8bf4247c9bf4f2337b81ad4ddad, d8202786b3d75125c84ebc4de6d946f92fde0ee8, bb0d384c1f42a5b7ace0bd88fee80b9bb1d49acb +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ fa5e08156335d0687c85b4e724db9448fb166601, < e610fb113cdfa8bf4247c9bf4f2337b81ad4ddad
Fixed in
  • e610fb113cdfa8bf4247c9bf4f2337b81ad4ddad
LinuxLinuxAffected
  • ≥ fa5e08156335d0687c85b4e724db9448fb166601, < d8202786b3d75125c84ebc4de6d946f92fde0ee8
Fixed in
  • d8202786b3d75125c84ebc4de6d946f92fde0ee8
LinuxLinuxAffected
  • ≥ fa5e08156335d0687c85b4e724db9448fb166601, < bb0d384c1f42a5b7ace0bd88fee80b9bb1d49acb
Fixed in
  • bb0d384c1f42a5b7ace0bd88fee80b9bb1d49acb
LinuxLinuxAffected
  • ≥ fa5e08156335d0687c85b4e724db9448fb166601, < 883962731420ec271ed8c1cd76524f4b17faa982
Fixed in
  • 883962731420ec271ed8c1cd76524f4b17faa982
LinuxLinuxAffected
  • ≥ fa5e08156335d0687c85b4e724db9448fb166601, < 74580fdf022909e184223cacc364feb826982d96
Fixed in
  • 74580fdf022909e184223cacc364feb826982d96
LinuxLinuxAffected
  • ≥ fa5e08156335d0687c85b4e724db9448fb166601, < 55287a3555ff0515b3aff181d2c08c0462a41709
Fixed in
  • 55287a3555ff0515b3aff181d2c08c0462a41709

AI-suggested

The vulnerability description states it has been resolved by rejecting VAT headers with invalid length, indicating a fix is available or planned. If you cannot patch yet, avoid mounting untrusted UDF images with virtual partitions.

Description

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.

References

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