CVE-2026-63833CWE-862broken-access-control

CVE-2026-63833

High · published July 19, 2026

CVSS v3.1
7.1
EPSS
0%
Percentile
1.3
In the wild
Unconfirmed
What it is

In the Linux kernel, the following vulnerability has been resolved:

ntfs3: reject direct userspace writes to reserved $LX* xattrs

NTFS3 uses $LXUID, $LXGID, $LXMOD and $LXDEV as internal WSL

permission metadata and reloads them into i_uid, i_gid and i_mode

from ntfs_get_wsl_perm().

Because the empty-prefix xattr handler also lets file owners call

setxattr() on these names directly, an unprivileged writer on a

writable ntfs3 mount can plant root ownership and S_ISUID on their own

file and gain euid 0 after inode reload.

Reject direct userspace writes to the reserved $LX* names. Internal

ntfs3 metadata updates are unchanged because ntfs_save_wsl_perm()

writes them via ntfs_set_ea() directly.

[[email protected]: added an additional check for non privileged users]

The record
Technical detail
CVSS v3.1
7.1 · HIGH
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00111 · 1.3th percentile
Weakness
CWE-862 · Missing Authorization
Published
2026-07-19T16:16Z
Affected products (6)
ProductVersionsFixed in
linux/linux_kernel≥ 5.15, < 5.15.2115.15.211
linux/linux_kernel≥ 5.16, < 6.1.1776.1.177
linux/linux_kernel≥ 6.2, < 6.6.1446.6.144
linux/linux_kernel≥ 6.7, < 6.12.956.12.95
linux/linux_kernel≥ 6.13, < 6.18.386.18.38
linux/linux_kernel≥ 6.19, < 7.1.37.1.3
References (7)
EPSS history
Timeline
  • 19 JUL 12:02Z
    ntfs3: reject direct userspace writes to reserved $LX* xattrs
    cvelistv5