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VulnerabilityPublished

CVE-2026-64322: Linux kernel · udf: validate sparing table length as an entry count, not a byte count

Source GCVE Database

0
Authoritative record:CVE-2026-64322· High 7.8

Not known to be exploited · CVSS 7.8 High · fixed in eeb0f3e193f8e523d03e4c9e084f6b4875f50e8e : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in eeb0f3e193f8e523d03e4c9e084f6b4875f50e8e, 7285276aa50d2839afb5957ffd491ad282dc8f72, 7f7774b9da0ef17b87bfa238cf966ad0b3376150 +10
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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
  • >=2.6.32.60 <2.6.33
  • >=2.6.34.14 <2.6.35
  • >=3.0.37 <3.1
  • >=3.2.23 <3.3
  • >=3.4.5 <3.5
Fixed in
  • eeb0f3e193f8e523d03e4c9e084f6b4875f50e8e
  • 7285276aa50d2839afb5957ffd491ad282dc8f72
  • 7f7774b9da0ef17b87bfa238cf966ad0b3376150
  • 04f4599a9efb90992d072a814960edf0cd62805d
  • 3ec997bd5508e9b25210b5bbec89031629cdb093
  • 3.5
  • 3.3
  • 3.1
  • 2d726135099313958f8975532a2e15322ff150ce
  • 2a219acb2ce674d99bbd1b7b35ed8c384dac7200
  • 2.6.35
  • 2.6.33
  • 0a9b79a951cfd70a9d31ca01ae2d08a20bb730e9
LinuxLinuxAffected
  • =3.5
Fixed in–

AI-suggested

If you cannot patch yet, avoid mounting untrusted UDF filesystem images to mitigate risk.

Description

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().

References

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