CVE-2026-109676
Description
A flaw was found in FreeRDP. When a user connects to a malicious Remote Desktop Protocol (RDP) server, the server can trigger an invalid smartcard connect operation, leading to a use-after-free vulnerability where previously released memory is accessed. A remote attacker can exploit this issue to cause memory corruption, potentially leading to arbitrary code execution or a Denial of Service (DoS) through an application crash.
Statement
This flaw is rated Important because a malicious RDP peer can trigger memory corruption in the FreeRDP client after the user connects (UI:R), with potential impact beyond a simple crash. Red Hat heap/allocator hardening and ASLR raise exploitation difficulty but do not justify lowering Confidentiality/Integrity/Availability in the base score when corruption is confirmed. This is the highest-severity issue in this FreeRDP set (CVSS 8.8) but remains Important rather than Critical because exploitation requires the user to connect to a malicious RDP server (UI:R).
Mitigation
If smartcard redirection is not required, disable it on the FreeRDP client. Restrict connections to trusted RDP servers.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.8 | N/A | 8.8 |
| 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 | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Red Hat CVSS v3 Score Explanation
Red Hat CVSS reflects FreeRDP exposure after applying client/server interaction model. Score 8.8 maps to IMPORTANT.
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory
The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.
Confidentiality
Technical Impact: Read Memory
Read operations on freed memory can sometimes leak sensitive information instead of causing a crash
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.
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