CVE-2023-53566

Medium

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_set_rbtree: fix null deref on element insertion There is no guarantee that rb_prev() will not return NULL in nft_rbtree_gc_elem(): general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] nft_add_set_elem+0x14b0/0x2990 nf_tables_newsetelem+0x528/0xb30 Furthermore, there is a possible use-after-free while iterating, 'node' can be free'd so we need to cache the next value to use.

Package Linux Kernel
Published 2025-10-04
Last modified 2026-03-21
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-476

CVE-2023-53566 is a NULL Pointer Dereference vulnerability

What is NULL Pointer Dereference?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.10.166, 5.15.91, 6.1.9, 6.2 and later are affected. Fixed in 5.10.181, 5.15.113, 6.1.30, 6.3.4, 6.4 and their respective stable series.

Affected from
≥ 5.10.166 ≥ 5.15.91 ≥ 6.1.9 ≥ 6.2
Fixed in
✓ 5.10.181 5.10.x ✓ 5.15.113 5.15.x ✓ 6.1.30 6.1.x ✓ 6.3.4 6.3.x ✓ 6.4

References

The following references provide additional information about CVE-2023-53566 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2023-53566?

    CVE-2023-53566 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 5.10.166 onward and has been patched in 5.10.181, 5.15.113, 6.1.30 and others. CVE-2023-53566 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2023-53566?

    CVE-2023-53566 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2023-53566?

    Yes — CVE-2023-53566 has been patched. Fixed versions include 5.10.181, 5.15.113, 6.1.30 and others. If you are running Linux kernel 5.10.166 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2023-53566 actively exploited?

    No — CVE-2023-53566 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is NULL Pointer Dereference (CWE-476)?

    The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. View CWE-476 on MITRE CWE →