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High

Remote Code Execution in Microsoft Remote Desktop Client

IdentifiersCVE-2026-48563CWE-416· Use After Free

CVE-2026-48563 is a critical remote code execution vulnerability in the Microsoft Remote Desktop Client. The provided content describes the issue as a heap-based buffer overflow / heap-based memory corruption condition in the client that can be triggered when a victim connects to an attacker-controlled Remote Desktop Server. Microsoft’s associated metadata in the supplied content maps the flaw to CWE-416, indicating a use-after-free condition underlying the memory corruption. Successful exploitation requires the attacker to win a race condition during processing by the vulnerable Remote Desktop Client, after which arbitrary code execution can occur on the victim system.

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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 remote attacker controlling a malicious Remote Desktop Server to execute code on the victim machine when the victim connects using a vulnerable Remote Desktop Client. The supplied CVSS metadata indicates high impact to confidentiality, integrity, and availability, meaning compromise could enable full execution in the client context with resulting data theft, tampering, or system instability/crash.

Mitigation

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

Until patches are fully deployed, reduce exposure by preventing users and systems with vulnerable Remote Desktop Client versions from connecting to untrusted or attacker-controlled Remote Desktop Servers. Restrict outbound RDP usage to trusted servers, apply network and administrative controls to limit who can initiate RDP sessions, and monitor for unusual RDP connection attempts to non-approved hosts.

Remediation

Patch, then assume compromise.

Apply the Microsoft security update released for CVE-2026-48563 in the June 2026 Patch Tuesday cycle for affected Remote Desktop Client versions. The provided content states that Microsoft has issued an official fix.
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 Clientapplication
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 2019operating_system
Microsoft CorporationWindows Server 2022operating_system
Microsoft CorporationWindows Server 2025operating_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 activity

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