CVE-2023-53566 | netfilter: nft_set_rbtree: fix null deref on element insertion

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.

Published: 2025-10-04 Last update: 2026-03-21 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-53566 is rated Low Risk (23.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-53566

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-10-05 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-53566

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]

Weakness enumeration for CVE-2023-53566

OS Trackers for CVE-2023-53566

vendor priority summary link
debian not yet assigned CVE-2023-53566 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-53566
redhat medium — https://access.redhat.com/security/cve/CVE-2023-53566
suse medium — https://www.suse.com/security/cve/CVE-2023-53566/
ubuntu medium CVE-2023-53566 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1414 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1017, ignored 158, not-affected 122, released 116, needs-triage 1. https://ubuntu.com/security/CVE-2023-53566

Affected software / configurations for CVE-2023-53566

Vendor Product Version Raw CPE
linux linux_kernel >= 5.10.166, < 5.10.181 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.15.91, < 5.15.113 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.1.9, < 6.1.30 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2.1, < 6.3.4 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 6.2 cpe:2.3:o:linux:linux_kernel:6.2:-:*:*:*:*:*:*
linux linux_kernel 6.2 cpe:2.3:o:linux:linux_kernel:6.2:rc6:*:*:*:*:*:*
linux linux_kernel 6.2 cpe:2.3:o:linux:linux_kernel:6.2:rc7:*:*:*:*:*:*
linux linux_kernel 6.2 cpe:2.3:o:linux:linux_kernel:6.2:rc8:*:*:*:*:*:*
linux linux_kernel 6.4 cpe:2.3:o:linux:linux_kernel:6.4:rc1:*:*:*:*:*:*
linux linux_kernel 6.4 cpe:2.3:o:linux:linux_kernel:6.4:rc2:*:*:*:*:*:*

References for CVE-2023-53566

cvelogic Threat Intelligence