CVE-2026-67306
Description
A flaw was found in FreeRDP. An out-of-bounds read vulnerability exists in the RDP6 planar RLE bitmap decoder. A malicious or compromised Remote Desktop Protocol (RDP) server can send a specially crafted bitmap or surface update. This can cause the client to read beyond the intended memory buffer, potentially leading to a denial of service (client crash) or the disclosure of sensitive information.
Statement
Successful exploitation requires user interaction or specific client connection behavior. An attacker cannot trigger this vulnerability remotely on an arbitrary client system without the client actively initiating an RDP session to a malicious or compromised RDP server.
The out-of-bounds read vulnerability is strictly contained within the client application process. It primarily results in an application crash leading to a localized Denial of Service (DoS), or potentially exposing limited client process memory, but it does not enable arbitrary code execution, privilege escalation, or systemic compromise of the host system
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
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 | 5.4 | N/A | 5.4 |
| 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 | Low | N/A | Low |
| Integrity Impact | None | N/A | None |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
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