CVE-2026-64322: Linux kernel · Out-of-bounds Write
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in eeb0f3e193f8e523d03e4c9e084f6b4875f50e8e : patch Linux kernel soon.
Data as of 26 Oct 2026, 13:47 UTC
- 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.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
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
- git.kernel.org/stable/c/eeb0f3e193f8e523d03e4c9e084f6b4875f50e8e (opens in a new tab)
- git.kernel.org/stable/c/0a9b79a951cfd70a9d31ca01ae2d08a20bb730e9 (opens in a new tab)
- git.kernel.org/stable/c/2d726135099313958f8975532a2e15322ff150ce (opens in a new tab)
- git.kernel.org/stable/c/7285276aa50d2839afb5957ffd491ad282dc8f72 (opens in a new tab)
- git.kernel.org/stable/c/2a219acb2ce674d99bbd1b7b35ed8c384dac7200 (opens in a new tab)
- git.kernel.org/stable/c/04f4599a9efb90992d072a814960edf0cd62805d (opens in a new tab)
- git.kernel.org/stable/c/7f7774b9da0ef17b87bfa238cf966ad0b3376150 (opens in a new tab)
- git.kernel.org/stable/c/3ec997bd5508e9b25210b5bbec89031629cdb093 (opens in a new tab)