CVE-2026-89487
Description
A flaw was found in openvswitch in the Linux kernel. This vulnerability occurs when the queue_userspace_packet() function incorrectly modifies a shared network packet buffer by stripping a critical flag. This action can lead to an unprivileged page-cache write, allowing a local attacker to modify data in memory that they should not have access to. This could potentially result in information disclosure or privilege escalation.
Statement
This vulnerability is rated as having an Important severity because an unprivileged local attacker can leverage improper packet buffer flag handling in the Open vSwitch subsystem to achieve unauthorized page-cache writes and elevate privileges. Successful exploitation requires specific zero-copy network traffic to traverse active Open vSwitch datapath flows, introducing configuration prerequisites. Default Red Hat Enterprise Linux installations do not load the Open vSwitch module unless explicitly configured or deployed in container platforms like Red Hat OpenShift.
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 | 7 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | High | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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