Out-of-bounds write in Linux kernel - CVE-2026-64296
Published: July 27, 2026
Vulnerability identifier: #VU139682
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64296
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause an out-of-bounds read and write.
The vulnerability exists due to an out-of-bounds write in exfat_find_dir_entry() when parsing crafted exfat directory entries containing many short name fragments. A local user can provide a crafted directory structure to cause an out-of-bounds read and write.
The issue occurs because the per-entry output pointer advances by a fixed amount while the tracked accumulated name length can remain smaller when a name fragment contains an early NUL.
Affected software
Linux kernel
How to mitigate CVE-2026-64296
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/33c0b96d7e1672be1de0053786637ea46fb81507
- https://git.kernel.org/stable/c/3a1230e7b043c62737b05a3e9275ca83a43ad20a
- https://git.kernel.org/stable/c/727bf7783a2936ffd55c628dddfd69343e511dcf
- https://git.kernel.org/stable/c/72a2589d82eb001c94b74bcfe6f9a599bd9bef60
- https://git.kernel.org/stable/c/c8e041c68c0bbb73aa62371ee63947bb6949d8b2
- https://git.kernel.org/stable/c/ce4736c1e6c4cfbf1ac409a8c328a0b69546c9a0
- https://git.kernel.org/stable/c/cf85180b8a015029ee147694eaf4e0b3537e9432
- https://git.kernel.org/stable/c/fae76a94b35ee8c0e2eb6f64caca01d75c6d34e4