Out-of-bounds write in Linux kernel - CVE-2026-64402
Published: July 27, 2026
Vulnerability identifier: #VU139572
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64402
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to an out-of-bounds write in smb_sync_perf_buffer() when copying hardware trace data into perf AUX ring buffer pages. A local user can trigger the vulnerable code path to cause a denial of service.
The issue occurs when the SMB sink is used as a perf AUX sink.
Affected software
Linux kernel
How to mitigate CVE-2026-64402
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/38dbc8db8341ccdf8e1e1a067453d33ad751864b
- https://git.kernel.org/stable/c/4c5a0a946373da99a80398289b28845b5ae40cd1
- https://git.kernel.org/stable/c/661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb
- https://git.kernel.org/stable/c/98495b5a4d77dd22e106f462b76e1093a55b29a7
- https://git.kernel.org/stable/c/daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f