Linux Kernel up to 7.1.2 Ntfs3 setxattr LXUID/LXGID/LXMOD/LXDEV permission

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
8.4	$0-$5k	2.16

Summaryinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 7.1.2. This issue affects the function setxattr of the component Ntfs3. Performing a manipulation of the argument LXUID/LXGID/LXMOD/LXDEV results in permission. This vulnerability is known as CVE-2026-63833. Attacking locally is a requirement. No exploit is available.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 7.1.2. This affects the function setxattr of the component Ntfs3. The manipulation of the argument LXUID/LXGID/LXMOD/LXDEV with an unknown input leads to a permission vulnerability. CWE is classifying the issue as CWE-275. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE 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 advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-63833 since 07/19/2026. The exploitability is told to be easy. An attack has to be approached locally. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/20/2026). MITRE ATT&CK project uses the attack technique T1222 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 327894 (Linux Distros Unpatched Vulnerability : CVE-2026-63833), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.15.211, 6.1.177, 6.6.144, 6.12.95, 6.18.38, 7.1.3 or 7.2-rc1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (327894). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.15.210
• 6.1.176
• 6.6.143
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
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• 6.12.88
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• 6.12.93
• 6.12.94
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
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• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 7.1.0
• 7.1.1
• 7.1.2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.8
VulDB Meta Temp Score: 8.4

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Permission
CWE: CWE-275 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 327894
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-63833

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.15.211/6.1.177/6.6.144/6.12.95/6.18.38/7.1.3/7.2-rc1

Timelineinfo

07/19/2026 Advisory disclosed
07/19/2026 +0 days CVE reserved
07/19/2026 +0 days VulDB entry created
07/20/2026 +1 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-63833 (🔒)
GCVE (CVE): GCVE-0-2026-63833
GCVE (VulDB): GCVE-100-380505

Entryinfo

Created: 07/19/2026 21:03
Updated: 07/20/2026 07:15
Changes: 07/19/2026 21:03 (56), 07/20/2026 07:15 (2)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

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