What is CVE-2026-64421?

CVE-2026-64421 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 6.4 onward and patched in 6.6.145, 6.12.97, 6.18.40 and others. CVE-2026-64421 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-64421?

CVE-2026-64421 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-2026-64421?

Yes, CVE-2026-64421 has been patched. Fixed versions include 6.6.145, 6.12.97, 6.18.40 and others. If you are running Linux kernel 6.4 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-64421 actively exploited?

CVE-2026-64421 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-2026-64421

High

In the Linux kernel, the following vulnerability has been resolved: media: nxp: imx8-isi: Fix use-after-free on remove KASAN reports a slab-use-after-free in __media_entity_remove_link() during rmmod of imx8_isi: BUG: KASAN: slab-use-after-free in __media_entity_remove_link+0x608/0x650 Read of size 2 at addr ffff0000d47cb02a by task rmmod/724 Call trace: __media_entity_remove_link+0x608/0x650 __media_entity_remove_links+0x78/0x144 __media_device_unregister_entity+0x150/0x280 media_device_unregister_entity+0x48/0x68 v4l2_device_unregister_subdev+0x158/0x300 v4l2_async_unbind_subdev_one+0x22c/0x358 v4l2_async_nf_unbind_all_subdevs+0xfc/0x1c0 v4l2_async_nf_unregister+0x5c/0x14c mxc_isi_remove+0x124/0x2a0 [imx8_isi] Allocated by task 249: __kmalloc_noprof+0x27c/0x690 mxc_isi_crossbar_init+0x22c/0x560 [imx8_isi] Freed by task 724: kfree+0x1e4/0x5b0 mxc_isi_crossbar_cleanup+0x34/0x80 [imx8_isi] mxc_isi_remove+0x11c/0x2a0 [imx8_isi] The problem is that mxc_isi_remove() calls mxc_isi_crossbar_cleanup() before mxc_isi_v4l2_cleanup(). The crossbar cleanup frees the media entity pads, but the subsequent v4l2 cleanup still tries to remove media links that reference those pads. Fix this by calling mxc_isi_v4l2_cleanup() before mxc_isi_crossbar_cleanup() to ensure all media entities are properly unregistered while the pads are still valid.

Package Linux Kernel

Published 2026-07-25

Last modified 2026-09-04

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-2026-64421 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 6.4 and later are affected. Fixed in 6.6.145, 6.12.97, 6.18.40, 7.1.4, 7.2 and their respective stable series.

Affected from

≥ 6.4

Fixed in

✓ 6.6.145 6.6.x ✓ 6.12.97 6.12.x ✓ 6.18.40 6.18.x ✓ 7.1.4 7.1.x ✓ 7.2

References

5 total

Kernel Git
https://git.kernel.org/stable/c/b670bf89824ede5d07d20bb9bfbafb754846081d

Patch
Kernel Git
https://git.kernel.org/stable/c/ba2aa5d325270cd965c44458c5ff5ab555e6af51

Patch
Kernel Git
https://git.kernel.org/stable/c/c12a5b2261351cd3b03921ce4720332ff5184b50

Patch
Kernel Git
https://git.kernel.org/stable/c/d22fb719654bfde6f682c9f14629f5f9534175b7

Patch
Kernel Git
https://git.kernel.org/stable/c/ef382a6baf0a95cf199fdf6bba2fd08e58b0a249

Patch

Details

CVE ID CVE-2026-64421

Severity High

CVSS score 7.8 / 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-2026-64421?

CVE-2026-64421 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 6.4 onward and has been patched in 6.6.145, 6.12.97, 6.18.40 and others. CVE-2026-64421 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-64421?

CVE-2026-64421 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-2026-64421?

Yes. CVE-2026-64421 has been patched. Fixed versions include 6.6.145, 6.12.97, 6.18.40 and others. If you are running Linux kernel 6.4 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-64421 actively exploited?

No. CVE-2026-64421 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.