CVE-2023-4244: Use-after-free in Linux kernel's netfilter: nf_tables component

Severity: high (CVSS 7.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-09-06 · updated 2026-07-30
Weakness: CWE-416

Description

A use-after-free vulnerability in the Linux kernel's netfilter: nf_tables component can be exploited to achieve local privilege escalation. Due to a race condition between nf_tables netlink control plane transaction and nft_set element garbage collection, it is possible to underflow the reference counter causing a use-after-free vulnerability. We recommend upgrading past commit 3e91b0ebd994635df2346353322ac51ce84ce6d8.

Affected products

Debian Linux: 10.0
Linux kernel: before 4.19.316; from 4.20 before 5.4.262; from 5.5 before 5.10.198; from 5.11 before 5.15.134; from 5.16 before 6.1.56; from 6.2.0 before 6.4.11 — fixed in 4.19.316, 5.10.198, 5.15.134, 5.4.262, 6.1.56, 6.4.11

How to fix

Upgrade to a fixed version: Linux kernel 4.19.316, 5.10.198, 5.15.134, 5.4.262. Check the vendor advisory for mitigations.

References

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