CVE-2026-72745
Description
A flaw was found in FreeRDP. A malicious peer, either a server or client, can exploit an out-of-bounds vulnerability during CredSSP/NLA authentication. By supplying a large 'extra count' (EC) value in a Kerberos GSS Wrap token, an attacker can cause the decryption operation to access memory outside of its intended buffer. This can lead to information disclosure, memory corruption, or a denial of service.
Statement
Critical: FreeRDP in Red Hat environments is susceptible to a critical out-of-bounds vulnerability during CredSSP/NLA authentication. A malicious peer, whether a server or client, can exploit this flaw by sending a malformed Kerberos GSS Wrap token, leading to information disclosure, memory corruption, or denial of service. This risk is present when a completed Kerberos NLA context is established.
Mitigation
To reduce exposure, restrict FreeRDP server access to trusted clients only. When using FreeRDP as a client, avoid connecting to untrusted RDP servers. If CredSSP/NLA authentication is not strictly required, consider using alternative, secure authentication methods or protocols if available and supported by your FreeRDP configuration.
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 | 9.8 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | None |
| Availability Impact | High | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
If the untrusted pointer is used in a read operation, an attacker might be able to read sensitive portions of memory.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If the untrusted pointer references a memory location that is not accessible to the program, or points to a location that is "malformed" or larger than expected by a read or write operation, the application may terminate unexpectedly.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands; Modify Memory
If the untrusted pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible.
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