ntfs3: reject direct userspace writes to reserved $LX* xattrs
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]
CVE-2026-63833
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-63833
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "be71b5cba2e6485e8959da7a9f9a44461a1bb074",
"lessThan": "e574af95234afc3c725988bbc1fdeb46b9f386a4",
"versionType": "git"
},
{
"status": "affected",
"version": "be71b5cba2e6485e8959da7a9f9a44461a1bb074",
"lessThan": "2c3cd6da4a14380ef79e34bd9dff7caf46687477",
"versionType": "git"
},
{
"status": "affected",
"version": "be71b5cba2e6485e8959da7a9f9a44461a1bb074",
"lessThan": "e8852ae29868e449fdb47eebc28f35fb80741a5f",
"versionType": "git"
},
{
"status": "affected",
"version": "be71b5cba2e6485e8959da7a9f9a44461a1bb074",
"lessThan": "f8d420949b335a4b51d06ab276beee6b8dfdc909",
"versionType": "git"
},
{
"status": "affected",
"version": "be71b5cba2e6485e8959da7a9f9a44461a1bb074",
"lessThan": "5e658b9245a52d838ef93729a7bc07de8e19deb7",
"versionType": "git"
},
{
"status": "affected",
"version": "be71b5cba2e6485e8959da7a9f9a44461a1bb074",
"lessThan": "293a84fa40b3a1b3471c0545722724bc10973f76",
"versionType": "git"
},
{
"status": "affected",
"version": "be71b5cba2e6485e8959da7a9f9a44461a1bb074",
"lessThan": "5b08dccecf825cbf905f348bc6ccb497507e28e2",
"versionType": "git"
}
],
"programFiles": [
"fs/ntfs3/xattr.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.15",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.15.211",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.177",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.144",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.95",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.38",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.3",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/ntfs3/xattr.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-63833
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #40844 · Revision 1
- Added to Heist Feed
- Publisher date