CVE-2026-63833

HIGH
MEDIUM Priority: 0.01 BB Relevance: 39/100
Published: 2026-07-19 Modified: 2026-10-22 First seen: 2026-10-29 Status: active

Attack Surface

Low Complexity No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Local
AC: Low
PR: Low
UI: None
S: Unchanged
C: High
I: High
A: None

Description

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. [almaz.alexandrovich@paragon-software.com: added an additional check for non privileged users]

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
linux linux_kernel 5.15 – 5.15.211

Bug Bounty Relevance

39 / 100
✓ Low complexity
✓ No user interaction

CVSS Score

7.1 / 10.0 v3.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

EPSS — Exploitation Probability

0.14%
Raw Score 0.001440
Percentile 3.7%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00144
2026-10-28
0.00144

Intelligence Sources

nvd ref →