CVE-2023-6817: Use-after-free in Linux kernel's netfilter: nf_tables component

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-12-18 · updated 2026-10-14
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. The function nft_pipapo_walk did not skip inactive elements during set walk which could lead double deactivations of PIPAPO (Pile Packet Policies) elements, leading to use-after-free. We recommend upgrading past commit 317eb9685095678f2c9f5a8189de698c5354316a.

Affected products

Linux kernel: from 5.6 before 5.10.204; from 5.11 before 5.15.143; from 5.16 before 6.1.68; from 6.2 before 6.6.7; 6.7-rc1, 6.7-rc2, 6.7-rc3, 6.7-rc4 — fixed in 5.10.204, 5.15.143, 6.1.68, 6.6.7

How to fix

Upgrade to a fixed version: Linux kernel 5.10.204, 5.15.143, 6.1.68, 6.6.7. Check the vendor advisory for mitigations.

References

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