CVE-2026-64393
Linux Kernel vulnerability
- Published25 Jul 2026
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.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:HAffected products
Remediation
- https://git.kernel.org/stable/c/0ce682867fd506f61f40c76bde7e4205bde34e87
- https://git.kernel.org/stable/c/20ee516a62989a8d505ee432f9e59525ea23984e
- https://git.kernel.org/stable/c/5cbabf3a71575cd31bc7785d92d4ab42338a654b
- https://git.kernel.org/stable/c/8cc9ec711f5255167247a9ab6a7179b787426ed7
- https://git.kernel.org/stable/c/b35afd5cf8fab236ef21117e42ee45691d4ffa7b
- https://git.kernel.org/stable/c/b383bcad3d2fe634b26efbce53e22bbb5753a520
References
- https://git.kernel.org/stable/c/0ce682867fd506f61f40c76bde7e4205bde34e87
- https://git.kernel.org/stable/c/20ee516a62989a8d505ee432f9e59525ea23984e
- https://git.kernel.org/stable/c/5cbabf3a71575cd31bc7785d92d4ab42338a654b
- https://git.kernel.org/stable/c/8cc9ec711f5255167247a9ab6a7179b787426ed7
- https://git.kernel.org/stable/c/b35afd5cf8fab236ef21117e42ee45691d4ffa7b
- https://git.kernel.org/stable/c/b383bcad3d2fe634b26efbce53e22bbb5753a520
Frequently asked
Is CVE-2026-64393 being actively exploited?
CVE-2026-64393 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.70%.
How severe is CVE-2026-64393?
CVE-2026-64393 has a CVSS 3.1 base score of 9.1, rated critical. EPSS estimates a 0.70% probability of exploitation.
Which products are affected by CVE-2026-64393?
Affected products include Linux Kernel.
How do I fix CVE-2026-64393?
Upgrade affected software to a fixed version, for example Linux Kernel 6.1.178 or later, then confirm no affected versions remain in your inventory.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-64393 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.