CVE-2026-109939
Description
A flaw was found in FreeRDP. A malicious or compromised Remote Desktop Protocol (RDP) server can cause a Denial of Service (DoS) by crashing the client application during connection establishment. By sending a specially crafted bitmap cache order before connection initialization completes, the server triggers a null pointer dereference in the client parser. This issue prevents users from establishing remote desktop connections when bitmap caching features are enabled.
Statement
This flaw is rated Moderate because a malicious or compromised RDP server can crash the FreeRDP client when Cache Bitmap V3 order handling 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
Red Hat CVSS v3 Score Explanation
Red Hat CVSS reflects FreeRDP exposure after applying client/server interaction model. Score 6.5 maps to MODERATE.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
