CVE-2026-110834
Description
A flaw was found in FreeRDP. A malicious Remote Desktop Protocol (RDP) server can cause a Denial of Service (DoS) by sending read or write requests for a redirected serial device before the device is opened or after it has been closed. Because FreeRDP does not verify that the serial communication handle is active before handling these requests, it encounters a null pointer dereference (an attempt to access invalid memory), causing the client application to terminate abruptly.
Statement
This flaw is rated Moderate because a malicious or compromised RDP server can crash the FreeRDP client when out-of-lifecycle serial redirection requests is used, causing a denial of service for the connecting user. Exploitation requires the user to initiate a connection (UI:R). Confidentiality and integrity are not impacted. Red Hat platform safeguards such as ASLR, NX, and FORTIFY_SOURCE do not remove the crash impact, so Availability remains High.
Mitigation
Restrict FreeRDP clients to trusted RDP servers and networks.
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 | 6.5 | N/A | 6.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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