CVE-2026-31424
Description
A flaw was found in the Linux kernel's netfilter subsystem, specifically within the x_tables and arptables components. This vulnerability arises when xt_match and xt_target extensions, registered for unspecified protocol families, are incorrectly processed by the Address Resolution Protocol (ARP) subsystem. An attacker could exploit this by crafting network packets that trigger a mismatch in hook validation, leading to a null pointer dereference and ultimately a kernel panic, resulting in a Denial of Service (DoS) for the affected system.
Statement
Incorrect extension registration for ARP chains is a correctness bug in the netfilter compatibility path. Exploitation for a panic requires a privileged user to install matching nftables/arptables rules that pull in the affected xt_* pieces on ARP traffic. The fix limits arptables to extensions explicitly declared for NFPROTO_ARP.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Other
Technical Impact: Varies by Context
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