What is CVE-2026-64259?

CVE-2026-64259 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-2026-64259 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-64259?

CVE-2026-64259 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-2026-64259?

Yes, CVE-2026-64259 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-2026-64259 actively exploited?

CVE-2026-64259 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-2026-64259

High

In the Linux kernel, the following vulnerability has been resolved: fuse-uring: make a fuse_req on SQE commit only findable after memcpy Bad userspace might try to trick us and send commit SQEs request unique / commit-id of requests that are not even send to fuse-server (io_uring_cmd_done() not called) yet. fuse_uring_commit_fetch() ends the fuse request when the ring entry has a wrong state, but that could have caused a use-after-free with the memcpy operations in fuse_uring_send_in_task(). In order to avoid such races the call of fuse_uring_add_to_pq() is moved after the copy operations and just before completing the io-uring request - malicious userspace cannot find the request anymore until all prepration work in fuse-client/kernel is completed. This also moves fuse_uring_add_to_pq() a bit up in the code to avoid a forward declaration. Also not with a preparation commit, to make it easier to back port to older kernels.

Package Linux Kernel

Published 2026-07-25

Last modified 2026-08-17

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-2026-64259 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/1efd3d474fc0ba74dfd984249bca78807d739812

Patch
Kernel Git
https://git.kernel.org/stable/c/a635f427d57e2012102ae4886b48d8955c59fb86

Patch
Kernel Git
https://git.kernel.org/stable/c/e1711479e9068ea31b31353a702a51e639c3d059

Patch

Details

CVE ID CVE-2026-64259

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2026-07-25

Modified 2026-08-17

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-64259?

CVE-2026-64259 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-2026-64259 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-64259?

CVE-2026-64259 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-2026-64259?

Yes. CVE-2026-64259 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-2026-64259 actively exploited?

No. CVE-2026-64259 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.