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Mallory
High

Windows Remote Desktop RDP File Spoofing Vulnerability

IdentifiersCVE-2026-26151CWE-451

CVE-2026-26151 is a spoofing vulnerability in Windows Remote Desktop / Remote Desktop Connection caused by insufficient UI warning of dangerous operations when opening Remote Desktop Protocol (RDP) files. The issue allows attacker-controlled RDP content to be presented without adequate warning to the user, enabling a remote, unauthorized attacker to induce the user to trust or launch a malicious remote desktop connection. Microsoft’s April 2026 security update introduced new warnings in the Remote Desktop Connection application when users open RDP files, indicating the vulnerable condition was the lack of sufficiently prominent security prompts around risky RDP file handling.

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For your environment

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows an unauthorized attacker to perform spoofing over a network. Based on the provided advisory context, the primary impact is major loss of confidentiality and limited loss of integrity, with no direct availability impact. In practice, the attacker can mislead a user into opening or trusting a malicious RDP configuration, potentially causing the user to connect to an attacker-controlled or attacker-influenced remote desktop endpoint and disclose credentials, session-related information, or other sensitive data under false pretenses.

Mitigation

If you can’t patch tonight, do this now.

Until patching is fully deployed, reduce exposure by preventing users from opening untrusted .rdp files and by treating RDP files from email, web downloads, chat, and other external sources as potentially malicious. Train users to heed Remote Desktop security prompts and verify the origin and destination of remote desktop connections before opening RDP files. Where feasible, use application control, attachment filtering, and mail/web gateway controls to limit delivery of attacker-controlled RDP files.

Remediation

Patch, then assume compromise.

Apply the Microsoft security update released beginning with the April 2026 security update for Windows Remote Desktop / the Remote Desktop Connection application. The update adds new security warnings when opening RDP files, addressing the insufficient-warning condition described in the advisory.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
Microsoft CorporationRemote Desktop Connectionapplication
Microsoft CorporationWindows 10 1607operating_system
Microsoft CorporationWindows 10 1809operating_system
Microsoft CorporationWindows 10 21h2operating_system
Microsoft CorporationWindows 10 22h2operating_system
Microsoft CorporationWindows 11 23h2operating_system
Microsoft CorporationWindows 11 24h2operating_system
Microsoft CorporationWindows 11 25h2operating_system
Microsoft CorporationWindows 11 26h1operating_system
Microsoft CorporationWindows Server 2012operating_system
Microsoft CorporationWindows Server 2012 R2operating_system
Microsoft CorporationWindows Server 2016operating_system
Microsoft CorporationWindows Server 2019operating_system
Microsoft CorporationWindows Server 2022operating_system
Microsoft CorporationWindows Server 2022 23h2operating_system
Microsoft CorporationWindows Server 2025operating_system
Microsoft CorporationWindows Server 23h2operating_system

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity2

Community discussion across Reddit, Mastodon, and other social sources.