CVE-2026-64399

Sažetak

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add permission checks for FSCTL_DUPLICATE_EXTENTS_TO_FILE The FSCTL_DUPLICATE_EXTENTS_TO_FILE arm of smb2_ioctl() overwrites the destination file's data via vfs_clone_file_range() with neither the share-level KSMBD_TREE_CONN_FLAG_WRITABLE check nor a per-handle fp->daccess check that the other write-bearing arms carry. A client can overwrite destination data on a read-only share, or from a handle opened with only FILE_WRITE_ATTRIBUTES (which still yields an FMODE_WRITE filp). FILE_WRITE_ATTRIBUTES-only destination handle overwrote the file's data via the clone. Add both checks, matching the FSCTL_SET_SPARSE permission fix; require FILE_WRITE_DATA since this writes data.

Reference

CVSS

Base:	9.8
Impact:	5.9
Exploitability:	3.9

Pristup

Vektor	Složenost	Autentikacija
NETWORK	LOW	NONE

Impact

Povjerljivost	Cjelovitost	Dostupnost
HIGH	HIGH	HIGH

CVSS vektor

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

Zadnje važnije ažuriranje

27-07-2026 - 05:16

Objavljeno

25-07-2026 - 10:17