CVE-2026-25942 – This vulnerability in FreeRDP allows a maliciou... (How to Fix)

Q: What is the severity of CVE-2026-25942?

CVE-2026-25942 has a CVSS score of 7.5 (HIGH). This vulnerability in FreeRDP allows a malicious RDP server to trigger an out-of-bounds read by sending an execResult value of 7 or greater. This could potentially leak memory contents or cause crashes. All FreeRDP clients connecting to untrusted servers are affected.

📋 TL;DR

This vulnerability in FreeRDP allows a malicious RDP server to trigger an out-of-bounds read by sending an execResult value of 7 or greater. This could potentially leak memory contents or cause crashes. All FreeRDP clients connecting to untrusted servers are affected.

💻 Affected Systems

Products:

FreeRDP

Versions: All versions prior to 3.23.0

Operating Systems: Linux, Unix-like systems with X11

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects X11 client implementation (xf_rail.c). Other FreeRDP clients may not be affected.

📦 What is this software?

Freerdp by Freerdp

View all CVEs affecting Freerdp →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Information disclosure through memory leak leading to credential exposure or remote code execution if combined with other vulnerabilities

🟠

Likely Case

Client application crash (denial of service) or limited information disclosure

🟢

If Mitigated

No impact if patched version is used or if connecting only to trusted servers

🌐 Internet-Facing: MEDIUM - Requires connecting to malicious RDP server, but RDP clients often connect to various servers

🏢 Internal Only: LOW - Internal RDP servers are typically trusted, reducing attack surface

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploitation requires server-side control, making it client-side vulnerability. No authentication needed from client perspective.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 3.23.0

Vendor Advisory: https://github.com/FreeRDP/FreeRDP/commit/9362a0bf8dda04eedbca07d5dfaec1044e67cc6b

Restart Required: Yes

Instructions:

1. Update FreeRDP to version 3.23.0 or later. 2. For Linux systems: Use package manager (apt/yum) to update freerdp2 package. 3. For source builds: Download latest release from GitHub and recompile. 4. Restart any FreeRDP client applications.

🔧 Temporary Workarounds

Restrict RDP connections

all

Only connect to trusted RDP servers

Use alternative RDP client

all

Temporarily use different RDP client software

🧯 If You Can't Patch

Implement network segmentation to restrict RDP traffic to trusted servers only
Monitor for abnormal RDP connection attempts and client crashes

🔍 How to Verify

Check if Vulnerable:

Check FreeRDP version: xfreerdp --version. If version is below 3.23.0, system is vulnerable.

Check Version:

xfreerdp --version

Verify Fix Applied:

After update, verify version is 3.23.0 or higher: xfreerdp --version

📡 Detection & Monitoring

Log Indicators:

FreeRDP client crashes
Segmentation faults in FreeRDP processes

Network Indicators:

RDP connections to unknown/untrusted servers
Abnormal RDP traffic patterns

SIEM Query:

process.name:"xfreerdp" AND event.action:"crash" OR process.name:"xfreerdp" AND network.destination.ip:(not in trusted_servers)

📊 Metadata

CVE ID: CVE-2026-25942

CVSS v3 Score: 7.5 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-125

Published: February 25, 2026

Last Updated: February 27, 2026

🔗 References

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