CVE-2026-43379 CRITICAL

CVE-2026-43379: ksmbd: fix use-after-free in smb_lazy_parent_lease_break_close()

Vendor Linux
Product Linux
Published May 8, 2026
Last update May 23, 2026

CVSS base score

9.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

What the vulnerability does

01Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in smb_lazy_parent_lease_break_close() opinfo pointer obtained via rcu_dereference(fp->f_opinfo) is being accessed after rcu_read_unlock() has been called. This creates a race condition where the memory could be freed by a concurrent writer between the unlock and the subsequent pointer dereferences (opinfo->is_lease, etc.), leading to a use-after-free.

Key dates

02Disclosure timeline

May 8, 2026 CVE published
May 23, 2026 Record updated