Improper access control in Linux kernel - CVE-2026-52944
Published: June 25, 2026
Vulnerability identifier: #VU135434
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-52944
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a remote user to bypass permission checks and modify file sparse attributes.
The vulnerability exists due to improper access control in fsctl_set_sparse() when handling FSCTL_SET_SPARSE requests. A remote user can send a crafted FSCTL_SET_SPARSE request on an opened file to bypass permission checks and modify file sparse attributes.
The issue affects both clients on read-only shares and clients on writable shares that lack FILE_WRITE_DATA or FILE_WRITE_ATTRIBUTES access.
How to mitigate CVE-2026-52944
Install security update from vendor's repository.