CVE-2026-93519
Description
A flaw was found in xorg-x11-server. The server writes pointer barrier events into a fixed-size buffer without properly validating boundaries. An authenticated client can trigger this issue by configuring excessive pointer barriers and generating cursor motion events, causing a buffer overflow. This vulnerability may lead to arbitrary code execution or cause the server to crash, resulting in a Denial of Service (DoS).
Statement
This vulnerability is evaluated as having a Moderate severity for Red Hat Enterprise Linux because exploitation is restricted to an authenticated local user with access to an active X11 display session, preventing remote exploitation. A local client can trigger memory corruption within the display server by defining a large number of cursor barriers and subsequently generating pointer movement. While this flaw can lead to a crash of the display server or potentially execute code within the context of the running X server process, the blast radius is confined to the local graphical user session.
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 | 7.8 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | High | N/A | N/A |
| Integrity Impact | High | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
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