Out-of-bounds write in Linux kernel - CVE-2026-64322
Published: July 27, 2026
Vulnerability identifier: #VU139660
CSH Severity: Low
CVSS v4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64322
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to disclose sensitive information and corrupt memory.
The vulnerability exists due to out-of-bounds read and out-of-bounds write in udf sparing table handling in fs/udf/super.c when parsing a crafted UDF image. A local user can mount or otherwise trigger processing of a specially crafted UDF image to disclose sensitive information and corrupt memory.
The issue is caused by validating reallocationTableLen as a byte count even though it is later used as an entry count for sparingEntry array access.
Affected software
Linux kernel
How to mitigate CVE-2026-64322
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/04f4599a9efb90992d072a814960edf0cd62805d
- https://git.kernel.org/stable/c/0a9b79a951cfd70a9d31ca01ae2d08a20bb730e9
- https://git.kernel.org/stable/c/2a219acb2ce674d99bbd1b7b35ed8c384dac7200
- https://git.kernel.org/stable/c/2d726135099313958f8975532a2e15322ff150ce
- https://git.kernel.org/stable/c/3ec997bd5508e9b25210b5bbec89031629cdb093
- https://git.kernel.org/stable/c/7285276aa50d2839afb5957ffd491ad282dc8f72
- https://git.kernel.org/stable/c/7f7774b9da0ef17b87bfa238cf966ad0b3376150
- https://git.kernel.org/stable/c/eeb0f3e193f8e523d03e4c9e084f6b4875f50e8e