What is CVE-2026-64393?

CVE-2026-64393 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.1 out of 10, affecting Linux kernel versions from 5.15 onward and patched in 6.1.178, 6.6.145, 6.12.96 and others. CVE-2026-64393 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-64393?

CVE-2026-64393 has a CVSS score of 9.1 out of 10, rated Critical severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

Is there a patch available for CVE-2026-64393?

Yes, CVE-2026-64393 has been patched. Fixed versions include 6.1.178, 6.6.145, 6.12.96 and others. If you are running Linux kernel 5.15 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-64393 actively exploited?

CVE-2026-64393 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-64393

Critical

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.

Package Linux Kernel

Published 2026-07-25

Last modified 2026-09-04

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

9.1

out of 10

Critical

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

High

Availability

High

Vector string

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Affected versions

Linux kernel versions 5.15 and later are affected. Fixed in 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2 and their respective stable series.

Affected from

≥ 5.15

Fixed in

✓ 6.1.178 6.1.x ✓ 6.6.145 6.6.x ✓ 6.12.96 6.12.x ✓ 6.18.39 6.18.x ✓ 7.1.4 7.1.x ✓ 7.2

References

6 total

Kernel Git
https://git.kernel.org/stable/c/0ce682867fd506f61f40c76bde7e4205bde34e87

Patch
Kernel Git
https://git.kernel.org/stable/c/20ee516a62989a8d505ee432f9e59525ea23984e

Patch
Kernel Git
https://git.kernel.org/stable/c/5cbabf3a71575cd31bc7785d92d4ab42338a654b

Patch
Kernel Git
https://git.kernel.org/stable/c/8cc9ec711f5255167247a9ab6a7179b787426ed7

Patch
Kernel Git
https://git.kernel.org/stable/c/b35afd5cf8fab236ef21117e42ee45691d4ffa7b

Patch

Showing 5 of 6 references View all on NVD

Details

CVE ID CVE-2026-64393

Severity Critical

CVSS score 9.1 / 10

CVSS version 3.1

Published 2026-07-25

Modified 2026-09-04

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-64393?

CVE-2026-64393 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.1 out of 10 . It affects Linux kernel versions from 5.15 onward and has been patched in 6.1.178, 6.6.145, 6.12.96 and others. CVE-2026-64393 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-64393?

CVE-2026-64393 has a CVSS score of 9.1 out of 10, rated Critical severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.
Is there a patch available for CVE-2026-64393?

Yes. CVE-2026-64393 has been patched. Fixed versions include 6.1.178, 6.6.145, 6.12.96 and others. If you are running Linux kernel 5.15 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-64393 actively exploited?

No. CVE-2026-64393 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.