What is CVE-2026-64300?

CVE-2026-64300 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, classified as a Use After Free flaw (CWE-416), affecting Linux kernel versions from 6.14 onward and patched in 6.18.39, 7.1.4 and 7.2. CVE-2026-64300 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-64300?

CVE-2026-64300 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-64300?

Yes, CVE-2026-64300 has been patched. Fixed versions include 6.18.39, 7.1.4 and 7.2. If you are running Linux kernel 6.14 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-64300 actively exploited?

CVE-2026-64300 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Use After Free (CWE-416)?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/416.html

CVE-2026-64300

High

In the Linux kernel, the following vulnerability has been resolved: perf/aux: Fix page UAF in map_range() map_range() reads rb->aux_pages[], rb->aux_nr_pages and rb->aux_pgoff via perf_mmap_to_page() while holding only event->mmap_mutex. Those fields are serialized by rb->aux_mutex, and mmap_mutex is per event. Thus, two events sharing one rb via PERF_EVENT_IOC_SET_OUTPUT can race rb_alloc_aux() with map_range(), leading to a page-UAF scenario as follows: CPU 0 CPU 1 ===== ===== rb_alloc_aux() map_range() [1]: allocate rb->aux_pages[0] [2]: rb->aux_nr_pages++ [3]: perf_mmap_to_page() returns rb->aux_pages[0] [4]: map it as VM_PFNMAP [5]: rb->aux_pgoff = 1 munmap the page [6]: free rb->aux_pages[0] Pages mapped as VM_PFNMAP have no refcount protection, so CPU 1 holds a mapping to a freed physical frame. Fix this by taking rb->aux_mutex across the page walk in map_range().

Package Linux Kernel

Published 2026-07-25

Last modified 2026-09-03

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Weakness type

CWE-416

CVE-2026-64300 is a Use After Free vulnerability

What is Use After Free?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE

Affected versions

Linux kernel versions 6.14 and later are affected. Fixed in 6.18.39, 7.1.4, 7.2 and their respective stable series.

Affected from

≥ 6.14

Fixed in

✓ 6.18.39 6.18.x ✓ 7.1.4 7.1.x ✓ 7.2

References

3 total

Kernel Git
https://git.kernel.org/stable/c/0cff05bd2186020f8706233e261016d149cc24db

Patch
Kernel Git
https://git.kernel.org/stable/c/5948aaf64f81f217a25dcc2bf6c0779bca19566c

Patch
Kernel Git
https://git.kernel.org/stable/c/c8b7e113f7b61eef2f017e6329c27c2331058c5a

Patch

Details

CVE ID CVE-2026-64300

Severity High

CVSS score 7.8 / 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-2026-64300?

CVE-2026-64300 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 6.14 onward and has been patched in 6.18.39, 7.1.4 and 7.2. CVE-2026-64300 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-64300?

CVE-2026-64300 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-64300?

Yes. CVE-2026-64300 has been patched. Fixed versions include 6.18.39, 7.1.4 and 7.2. If you are running Linux kernel 6.14 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-64300 actively exploited?

No. CVE-2026-64300 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.