What is CVE-2023-53088?

CVE-2023-53088 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 5.18.10 onward and patched in 6.1.22, 6.2.8 and 6.3. CVE-2023-53088 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2023-53088?

CVE-2023-53088 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-2023-53088?

Yes, CVE-2023-53088 has been patched. Fixed versions include 6.1.22, 6.2.8 and 6.3. If you are running Linux kernel 5.18.10 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2023-53088 actively exploited?

CVE-2023-53088 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-2023-53088

High

In the Linux kernel, the following vulnerability has been resolved: mptcp: fix UaF in listener shutdown As reported by Christoph after having refactored the passive socket initialization, the mptcp listener shutdown path is prone to an UaF issue. BUG: KASAN: use-after-free in _raw_spin_lock_bh+0x73/0xe0 Write of size 4 at addr ffff88810cb23098 by task syz-executor731/1266 CPU: 1 PID: 1266 Comm: syz-executor731 Not tainted 6.2.0-rc59af4eaa31c1f6c00c8f1e448ed99a45c66340dd5 #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x6e/0x91 print_report+0x16a/0x46f kasan_report+0xad/0x130 kasan_check_range+0x14a/0x1a0 _raw_spin_lock_bh+0x73/0xe0 subflow_error_report+0x6d/0x110 sk_error_report+0x3b/0x190 tcp_disconnect+0x138c/0x1aa0 inet_child_forget+0x6f/0x2e0 inet_csk_listen_stop+0x209/0x1060 __mptcp_close_ssk+0x52d/0x610 mptcp_destroy_common+0x165/0x640 mptcp_destroy+0x13/0x80 __mptcp_destroy_sock+0xe7/0x270 __mptcp_close+0x70e/0x9b0 mptcp_close+0x2b/0x150 inet_release+0xe9/0x1f0 __sock_release+0xd2/0x280 sock_close+0x15/0x20 __fput+0x252/0xa20 task_work_run+0x169/0x250 exit_to_user_mode_prepare+0x113/0x120 syscall_exit_to_user_mode+0x1d/0x40 do_syscall_64+0x48/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc The msk grace period can legitly expire in between the last reference count dropped in mptcp_subflow_queue_clean() and the later eventual access in inet_csk_listen_stop() After the previous patch we don't need anymore special-casing msk listener socket cleanup: the mptcp worker will process each of the unaccepted msk sockets. Just drop the now unnecessary code. Please note this commit depends on the two parent ones: mptcp: refactor passive socket initialization mptcp: use the workqueue to destroy unaccepted sockets

Package Linux Kernel

Published 2025-05-02

Last modified 2025-11-12

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-2023-53088 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 5.18.10, 5.19 and later are affected. Fixed in 6.1.22, 6.2.8, 6.3 and their respective stable series.

Affected from

≥ 5.18.10 ≥ 5.19

Fixed in

✓ 6.1.22 6.1.x ✓ 6.2.8 6.2.x ✓ 6.3

References

The following references provide additional information about CVE-2023-53088 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/0a3f4f1f9c27215e4ddcd312558342e57b93e518
Patch
Kernel patch commit
https://git.kernel.org/stable/c/0f4f4cf5d32f10543deb946a37111e714579511e
Patch
Kernel patch commit
https://git.kernel.org/stable/c/5564be74a22a61855f8b8c100d8c4abb003bb792
Patch

Details

CVE ID CVE-2023-53088

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2025-05-02

Modified 2025-11-12

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2023-53088?

CVE-2023-53088 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 5.18.10 onward and has been patched in 6.1.22, 6.2.8 and 6.3. CVE-2023-53088 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2023-53088?

CVE-2023-53088 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-2023-53088?

Yes — CVE-2023-53088 has been patched. Fixed versions include 6.1.22, 6.2.8 and 6.3. If you are running Linux kernel 5.18.10 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2023-53088 actively exploited?

No — CVE-2023-53088 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (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. View CWE-416 on MITRE CWE →