CVE-2026-63833 ntfs3: reject direct userspace writes to reserved $LX* xattrs

What is CVE-2026-63833?

CVE-2026-63833 is a high-severity vulnerability in Linux kernel, published on 19 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official 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.

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

Weakness: CWE-862

Which versions are affected by CVE-2026-63833?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-63833?

Apply the vendor's patch.

Is CVE-2026-63833 being exploited?

There is no known exploitation of CVE-2026-63833 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-92567, BELL-CVE-2026-63833, DEBIAN-CVE-2026-63833, GHSA-wv5h-jx62-4xcv, ROOT-OS-UBUNTU-2204-CVE-2026-63833, UBUNTU-CVE-2026-63833.