What is CVE-2023-53520?

CVE-2023-53520 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.7 out of 10, classified as a Race Condition flaw (CWE-362), affecting Linux kernel versions from 5.7 onward and patched in 5.15.199, 6.1.55, 6.5.5 and others. CVE-2023-53520 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2023-53520?

CVE-2023-53520 has a CVSS score of 4.7 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2023-53520?

Yes, CVE-2023-53520 has been patched. Fixed versions include 5.15.199, 6.1.55, 6.5.5 and others. If you are running Linux kernel 5.7 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2023-53520 actively exploited?

CVE-2023-53520 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is Race Condition (CWE-362)?

The product contains a code sequence that can run concurrently with other code, creating unexpected states. See MITRE CWE for full details: https://cwe.mitre.org/data/definitions/362.html

CVE-2023-53520

Medium

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: Fix hci_suspend_sync crash If hci_unregister_dev() frees the hci_dev object but hci_suspend_notifier may still be accessing it, it can cause the program to crash. Here's the call trace: <4>[102152.653246] Call Trace: <4>[102152.653254] hci_suspend_sync+0x109/0x301 [bluetooth] <4>[102152.653259] hci_suspend_dev+0x78/0xcd [bluetooth] <4>[102152.653263] hci_suspend_notifier+0x42/0x7a [bluetooth] <4>[102152.653268] notifier_call_chain+0x43/0x6b <4>[102152.653271] __blocking_notifier_call_chain+0x48/0x69 <4>[102152.653273] __pm_notifier_call_chain+0x22/0x39 <4>[102152.653276] pm_suspend+0x287/0x57c <4>[102152.653278] state_store+0xae/0xe5 <4>[102152.653281] kernfs_fop_write+0x109/0x173 <4>[102152.653284] __vfs_write+0x16f/0x1a2 <4>[102152.653287] ? selinux_file_permission+0xca/0x16f <4>[102152.653289] ? security_file_permission+0x36/0x109 <4>[102152.653291] vfs_write+0x114/0x21d <4>[102152.653293] __x64_sys_write+0x7b/0xdb <4>[102152.653296] do_syscall_64+0x59/0x194 <4>[102152.653299] entry_SYSCALL_64_after_hwframe+0x5c/0xc1 This patch holds the reference count of the hci_dev object while processing it in hci_suspend_notifier to avoid potential crash caused by the race condition.

Package Linux Kernel

Published 2025-10-01

Last modified 2026-04-06

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

4.7

out of 10

Medium

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

High

Vector string

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

Weakness type

CWE-362

CVE-2023-53520 is a Race Condition vulnerability

What is Race Condition?

The product contains a code sequence that can run concurrently with other code, creating unexpected states. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.7 and later are affected. Fixed in 5.15.199, 6.1.55, 6.5.5, 6.6 and their respective stable series.

Affected from

≥ 5.7

Fixed in

✓ 5.15.199 5.15.x ✓ 6.1.55 6.1.x ✓ 6.5.5 6.5.x ✓ 6.6

References

4 total

Kernel Git
https://git.kernel.org/stable/c/06e2b5ad72b60f90bfe565c201346532e271f484

Patch
Kernel Git
https://git.kernel.org/stable/c/573ebae162111063eedc6c838a659ba628f66a0f

Patch
Kernel Git
https://git.kernel.org/stable/c/e1fa25a91091bbed691ba2996a6cee809e3309a2

Patch
Kernel Git
https://git.kernel.org/stable/c/f9c8ce5d665653e3cf71a76349d41d7a7f7947e6

Patch

Details

CVE ID CVE-2023-53520

Severity Medium

CVSS score 4.7 / 10

CVSS version 3.1

Published 2025-10-01

Modified 2026-04-06

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2023-53520?

CVE-2023-53520 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.7 out of 10 , classified as a Race Condition flaw (CWE-362) . It affects Linux kernel versions from 5.7 onward and has been patched in 5.15.199, 6.1.55, 6.5.5 and others. CVE-2023-53520 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2023-53520?

CVE-2023-53520 has a CVSS score of 4.7 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2023-53520?

Yes. CVE-2023-53520 has been patched. Fixed versions include 5.15.199, 6.1.55, 6.5.5 and others. If you are running Linux kernel 5.7 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2023-53520 actively exploited?

No. CVE-2023-53520 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.