What is CVE-2026-64336?

CVE-2026-64336 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, classified as a Memory Leak flaw (CWE-401), affecting Linux kernel versions from 5.11 onward and patched in 5.15.212, 6.1.178, 6.6.145 and others. CVE-2026-64336 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-64336?

CVE-2026-64336 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-64336?

Yes, CVE-2026-64336 has been patched. Fixed versions include 5.15.212, 6.1.178, 6.6.145 and others. If you are running Linux kernel 5.11 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-64336 actively exploited?

CVE-2026-64336 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Memory Leak (CWE-401)?

The product does not release memory after use, causing gradual resource exhaustion. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/401.html

CVE-2026-64336

Medium

In the Linux kernel, the following vulnerability has been resolved: USB: serial: keyspan_pda: fix information leak The write() callback is supposed to return the number of characters accepted or a negative errno. Since the addition of write fifo support the keyspan_pda implementation will however return the number characters submitted to the device if the write urb is not already in use. If this number is larger than the number of characters passed to write(), the line discipline continues writing data from beyond the tty write buffer. Fix the information leak by making sure that keyspan_pda_write_start() returns zero on success as intended.

Package Linux Kernel

Published 2026-07-25

Last modified 2026-09-03

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Weakness type

CWE-401

CVE-2026-64336 is a Memory Leak vulnerability

What is Memory Leak?

The product does not release memory after use, causing gradual resource exhaustion. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.11 and later are affected. Fixed in 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4, 7.2 and their respective stable series.

Affected from

≥ 5.11

Fixed in

✓ 5.15.212 5.15.x ✓ 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

8 total

Kernel Git
https://git.kernel.org/stable/c/2f7a6b8ab3845bd1da02604f1a874b52a4555a72

Patch
Kernel Git
https://git.kernel.org/stable/c/6bfc8d01ac4068eced509f8fc74d0cd205e4dcec

Patch
Kernel Git
https://git.kernel.org/stable/c/b069b7029862fafaff331d4c664d97d4ae828d6d

Patch
Kernel Git
https://git.kernel.org/stable/c/cccef1711efbcdbe999738ac27d37b9ef6271abd

Patch
Kernel Git
https://git.kernel.org/stable/c/cf6ca0aefae03958cfb5b189b0adbfb25c06bfac

Patch

Showing 5 of 8 references View all on NVD

Details

CVE ID CVE-2026-64336

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-07-25

Modified 2026-09-03

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-64336?

CVE-2026-64336 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 5.11 onward and has been patched in 5.15.212, 6.1.178, 6.6.145 and others. CVE-2026-64336 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-64336?

CVE-2026-64336 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-64336?

Yes. CVE-2026-64336 has been patched. Fixed versions include 5.15.212, 6.1.178, 6.6.145 and others. If you are running Linux kernel 5.11 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-64336 actively exploited?

No. CVE-2026-64336 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.