CVE-2026-31495
Description
A flaw was found in the Linux kernel's netfilter connection tracking (ctnetlink) component. This vulnerability, related to improper input validation, allows an attacker to provide malformed netlink policy attributes. Specifically, invalid values for TCP window scaling (WSCALE) could lead to undefined behavior within the kernel. This could result in a system crash, causing a Denial of Service (DoS) for affected systems.
Statement
This Moderate-impact flaw in the Linux kernel's netfilter connection tracking (ctnetlink) component could lead to a system crash. A local attacker with low privileges could exploit improper input validation by providing malformed netlink policy attributes, specifically invalid TCP window scaling values, resulting in a Denial of Service.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
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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