CVE-2026-64393
Received Received - Intake

BaseFortify

Publication date: 2026-07-25

Last updated on: 2026-07-25

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: run set info with opener credentials SMB2 SET_INFO handlers call path-based VFS helpers after checking the access mask granted to the SMB handle. Those helpers perform their owner, inode permission and LSM checks using the current ksmbd worker credentials. Run the complete SET_INFO dispatch with the credentials captured when the handle was opened. This also removes the separate security information credential setup and keeps all SET_INFO classes under one credential scope. Direct override_creds() is used because it can nest with the request credential overrides already used by rename and link helpers.

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Meta Information

Published
2026-07-25
Last Modified
2026-07-25
Generated
2026-07-25
AI Q&A
2026-07-25
EPSS Evaluated
N/A
NVD
CVE-2026-64393
EUVD
EUVD-2026-48937

Affected Vendors & Products

Currently, no data is known.

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves ksmbd, a SMB server implementation. The issue occurs when SMB2 SET_INFO handlers use path-based VFS helpers that check permissions using the current worker credentials instead of the credentials from when the file handle was opened. This could allow unauthorized modifications if the current credentials have different access rights than those at handle creation.

Impact Analysis

If exploited, this vulnerability could allow an attacker with access to the system to perform unauthorized file modifications or information changes on SMB shares. This might lead to data corruption, unauthorized access to sensitive files, or privilege escalation depending on the system configuration and user permissions.

Compliance Impact

This vulnerability could potentially violate compliance requirements by allowing unauthorized access or modification of sensitive data stored on SMB shares. GDPR requires protection against unauthorized data access, while HIPAA mandates controls to prevent unauthorized changes to protected health information. Exploitation could lead to data breaches or integrity violations.

Mitigation Strategies

Update the Linux kernel to the latest patched version to resolve this ksmbd SET_INFO vulnerability. Monitor vendor advisories for kernel updates addressing this issue.

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