CVE-2026-63833

Linux kernel (GCP) vulnerabilities

criticalEPSS 0.1%

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]

Metrics

Severity
critical
no public PoC known
9.8
Source: nvd-v3
2.5 %
Low — this CVE sits in the lower 10% of all CVEs scored today.
0.1 %
Low — model estimates < 1% exploitation likelihood.
Published
2026-09-07 09:05 UTC

Reanalysis & status changes

Chronological NVD audit events for this CVE — reanalyses, CVSS updates, CPE diffs.

  1. CVE Modified2026-08-17 05:17 UTC· 416baaa9-dc9f-4396-8d5f-8c081fb06d67
    • Affected: Linux, LinuxLinux, Linux
  2. New CVE Received2026-07-19 12:16 UTC· 416baaa9-dc9f-4396-8d5f-8c081fb06d67
    • Affected: Linux, Linux
    • 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]
    • Reference: https://git.kernel.org/stable/c/293a84fa40b3a1b3471c0545722724bc10973f76
    • Reference: https://git.kernel.org/stable/c/2c3cd6da4a14380ef79e34bd9dff7caf46687477

Affected operating systems

  • linux

    redhat / enterprise_linux10.0

  • linux

    redhat / enterprise_linux7.0

  • linux

    redhat / enterprise_linux8.0

  • linux

    redhat / enterprise_linux9.0

  • linux

    ubuntu / linux-aws-6.8jammy

  • linux

    ubuntu / linux-azureresolute

  • linux

    ubuntu / linux-azuretrusty

  • linux

    ubuntu / linux-azurexenial

  • linux

    ubuntu / linux-azure-4.15bionic

  • linux

    ubuntu / linux-azure-5.4bionic

  • linux

    ubuntu / linux-azure-fdenoble

  • linux

    ubuntu / linux-azure-fderesolute

  • linux

    ubuntu / linux-azure-fde-6.8jammy

  • linux

    ubuntu / linux-azure-fipsbionic

  • linux

    ubuntu / linux-azure-fipsfocal

  • linux

    ubuntu / linux-azure-fipsnoble

  • linux

    ubuntu / linux-fipsjammy

  • linux

    ubuntu / linux-gcp-7.0noble

  • linux

    ubuntu / linux-gkejammy

  • linux

    ubuntu / linux-nvidia-tegranoble

  • linux

    ubuntu / linux-raspinoble

  • linux

    ubuntu / linux-raspi-realtimenoble

  • linux

    linux / linux_kernel2.6.12

  • linux

    linux / linux_kernel2.6.15

References & sources

Linked CVEs

Show 1392 more CVEs
IDCVE-2026-63833
Linux kernel (GCP) vulnerabilities — CVE-2026-63833 | NEOSEC Intel