CVE-2026-31692
Description
A flaw was found in the Linux kernel's rtnetlink component. An unprivileged local user, leveraging a user namespace, can exploit a missing CAP_NET_ADMIN capability check in the rtnl_newlink() function. This allows the user to create paired network devices in arbitrary network namespaces, including the init_net (initial network namespace). Such unauthorized creation of network interfaces could lead to unexpected network configurations and potential system instability or resource exhaustion.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.1 | 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 | High | 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:H/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)
Access Control,Confidentiality
Technical Impact: Gain Privileges or Assume Identity; Read Application Data; Read Files or Directories
An attacker may be able to access resources with the elevated privilege that could not be accessed with the attacker's original privileges. This is particularly likely in conjunction with another flaw, such as a buffer overflow.
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