CVE-2026-31579
Description
A flaw was found in the Linux kernel's WireGuard component. A local user could trigger a hung task by causing contention for the rtnl_lock() within the wg_netns_pre_exit() callback. This issue can lead to a Denial of Service (DoS), where the system becomes unresponsive as cleanup operations block indefinitely.
Statement
This Moderate flaw in the Linux kernel's WireGuard component allows a local attacker to trigger a Denial of Service. A local user can cause a hung task by creating contention for the rtnl_lock() during network namespace teardown. This vulnerability affects Red Hat Enterprise Linux 9 and 10.
Mitigation
To mitigate this issue, if the WireGuard VPN is not actively used, the `wireguard` kernel module can be prevented from loading. This can be achieved by creating a blacklist rule in `/etc/modprobe.d/`.
Example:
`echo "blacklist wireguard" | sudo tee /etc/modprobe.d/blacklist-wireguard.conf`
`sudo dracut -f`
A system reboot is required for the changes to take effect. This action will disable all WireGuard VPN functionality on the system.
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)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Other); DoS: Crash, Exit, or Restart
Each thread of execution will "hang" and prevent tasks from completing. In some cases, CPU consumption may occur if a lock check occurs in a tight loop.
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