CVE-2026-42985

Remote Desktop Client Remote Code Execution Vulnerability

No known exploitation. EPSS puts it in the 55th percentile. A vendor fix is available.

CVSS 3.18.8High EPSS percentile55th0.8% chance in 30 days CISA KEVNot listedNo confirmed exploitation
No public exploit known FixVendor fixNo build named by the sources

Published 2026-06-09Updated 2026-07-23Sources: CVE.org, NVD, BDU

NVD CVE.org

What to do

The vendor has published a fix. Version details are below where the sources state them.

Steps

Written by AI from the record

Check whether the device is running Remote Desktop Client / the Windows versions listed as affected (Windows 10, Windows 11, and Windows Server editions).
Verify the installed Remote Desktop Client / Windows build version and compare it to the fixed versions for your specific product line.
Install the vendor update that contains the fix for CVE-2026-42985 (use the Microsoft Update Guide for your exact platform).
If you can’t update immediately, reduce exposure by limiting access to Remote Desktop features and the network paths that could reach the Remote Desktop Client from outside your organization.

Vendor advisory Usually a quick update

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

Use after free in Remote Desktop Client allows an unauthorized attacker to execute code over a network.

In plain language

Written by AI from the record

This is a Remote Desktop Client weakness where a remote attacker may be able to run malicious code on your device without needing authentication, so you should update if you use Remote Desktop—this is a high-risk issue (RED).

CVE-2026-42985 is a remote code execution vulnerability in the Remote Desktop Client (heap-based buffer overflow) that can be triggered by an unauthorized network attacker without authentication (user interaction is required), leading to high impact on Windows devices running affected versions.

If you're affected

Malware running on company devices
Full compromise of affected machines
Data theft risk
Business disruption from downtime

What is it

Think of the Remote Desktop Client like a door to connect to your computers. This vulnerability is a coding flaw where a specially crafted network request could cause the program to “mis-handle” data and run attacker-controlled code. If an attacker can reach and trigger it, that could let them take over the affected device.

Who is affected

This matters if your business uses the Remote Desktop Client on Windows 10, Windows 11, or Windows Server (2012/2012 R2/2016/2019/2022/2025), because the bug is in the client-side Remote Desktop feature. The weakness does not require authentication, but it does require some user interaction, and network reachability is part of whether it can be abused.

How urgent is it

This is RED because it allows remote code execution over the network without needing authentication, which is exactly the kind of bug attackers try to weaponize. While no confirmed dated real-world incidents are provided in the findings, the attacker path is remote and the impact (code execution and device compromise) is severe, so patching should be treated as urgent.

What to do — in detail

Confirm exposure (what to check)

Identify which of your machines are running one of these: Windows 10, Windows 11, or Windows Server 2012, 2016, 2019, 2022, 2025 (and Windows Server 2012 R2).
Determine the installed Remote Desktop Client / Windows build number on each machine (for example, via your normal endpoint inventory or “About” / version reporting).

Determine whether you’re already safe

Compare your installed versions to the fixed versions provided by Microsoft:
- remote desktop client: fixed in 1.2.7214
- windows app: fixed in 2.0.1193.0
- windows 10: fixed in 10.0.14393.9234, 10.0.17763.8880, 10.0.19044.7417, 10.0.19045.7417
- windows 11: fixed in 10.0.22631.7219, 10.0.26100.8655, 10.0.26200.8655, 10.0.28000.2269
- windows server 2016: fixed in 10.0.14393.9234
- windows server 2019: fixed in 10.0.17763.8880
If your device’s version is already at or above the corresponding fixed build, you’re likely already protected.

Apply the fix

Install the Microsoft update for CVE-2026-42985 using the vendor’s update guidance:
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42985
Prioritize systems where Remote Desktop capabilities are used more frequently (workstations used by staff who connect out, and any machines acting as remote targets).

If patching is delayed (temporary risk reduction)

Restrict network paths so external parties cannot reach Remote Desktop Client-related services/features.
Limit which users can initiate Remote Desktop interactions from risky networks.
Segment or firewall remote access so that only intended internal sources can reach these components.

What to monitor after updating

Confirm update installation success in your endpoint management tooling.
Review for any unusual Remote Desktop-related activity or unexpected processes on machines (based on your normal monitoring practices).

Real-world exploitation status

The findings do not report clear dated exploitation incidents, and KEV does not list this CVE.
Even so, the issue is a remote code execution flaw, so you should patch promptly.

Technical context

Severity is high with a focus on remote code execution. The weakness is a heap-based buffer overflow (CWE-416) leading to arbitrary code execution (CWE-787) in the Remote Desktop Client. The findings describe exploitation as possible by a network attacker without authentication; user interaction is required, which means a user action (or a specific interaction flow) must occur for the attacker’s payload to be executed. KEV (CISA) does not list this CVE, and the findings state no public exploit code is on record and no clear dated real-world exploitation claim is provided. A PULSE actor name (“Nightmare Eclipse”) and press roundup attention are noted, but no confirmed exploitation details are included in the findings. The traffic-light verdict is RED, reflecting the remote code execution potential on supported Windows versions.

This is a general assessment based on public vulnerability data. It does not account for your specific infrastructure — when in doubt, consult a security specialist.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS55th

CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

0.8% chance of exploitation activity in the next 30 days, which ranks it in the 55th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

10 events over 44 days, from the signal feeds we watch.

2026-07-23Patch availablerecord updated
2026-07-09Patch availablerecord updated
2026-06-25OpenVAS check added
2026-06-15Patch availablerecord updated
2026-06-09Publishedweakness classified, att&ck mapped

Affected products

Microsoft Corpcommercial · USaka microsoft, microsoft corporation
- remote desktop clientDesktop AppOn-premConsumer Software
- windows appDesktop AppOn-premOperating Systems / windows
- Windows 10 Version 1607OSOn-premOperating Systems / windows
- Windows 11 version 23H2OSOn-premOperating Systems / windows
- Windows Server 2012 (Server Core installation)OSOn-premOperating Systems / windows
- Windows Server 2016 (Server Core installation)OSOn-premOperating Systems / windows
- Windows Server 2019 (Server Core installation)OSOn-premOperating Systems / windows
- Windows Server 2022 (Server Core installation)OSOn-premOperating Systems / windows

And 51 more affected products. See all after sign-in

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

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

Scored 8.8 by NVD.

How it is reached

Attack Vector NetworkExploitable remotely over the network without any special conditions
Attack Complexity LowNo special conditions — the attack can be reliably reproduced
Privileges Required NoneNo authentication required — anyone can exploit this
User Interaction RequiredA user must click a link, open a file, or perform some action

Scope

Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

Confidentiality HighTotal information disclosure — all data in the component is compromised
Integrity HighTotal loss of integrity — attacker can modify any data in the component
Availability HighTotal denial of service — the component is completely unavailable