SB2026081666 - Always-Incorrect Control Flow Implementation in Linux kernel netfilter

Description

This security bulletin contains information about 1 vulnerability.

1) Always-Incorrect Control Flow Implementation (CVE-ID: CVE-2026-72320)

CWE-ID: CWE-670 - Always-Incorrect Control Flow Implementation

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a local user to bypass netfilter rules.

The vulnerability exists due to improper handling of inverted lookups in nft_lookup_eval() when processing catchall elements for interval sets. A local user can trigger a crafted lookup condition to bypass netfilter rules.

The issue affects inverted lookups using catchall elements for the open-ended default range in interval sets.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0ab8880865f9678eb6174e72c1fc4712e44c745c
• https://git.kernel.org/stable/c/238c612357b5a25f03eacf356f95034f8551f218
• https://git.kernel.org/stable/c/e6107a4c74b54cb33e3bce162a63048ae5a6b198
• https://git.kernel.org/stable/c/ef0c7d4b04a0e6ad175323c24bc84e11470dd79d