Remote code execution via heap-based buffer overflow
Published Jun 9, 2026 · Updated Jun 9, 2026
Heap-based buffer overflow in the Microsoft Remote Desktop Client allows remote attackers to execute code through a malicious RDP server. The public Microsoft record does not identify the parsing routine or malformed protocol field whose length corrupts heap memory. Exploitation requires a user to connect the client to an attacker-controlled RDP server; successful code execution has the user's privileges.
Summary
What happened
Heap-based buffer overflow in the Microsoft Remote Desktop Client allows remote attackers to execute code through a malicious RDP server. The public Microsoft record does not identify the parsing routine or malformed protocol field whose length corrupts heap memory. Exploitation requires a user to connect the client to an attacker-controlled RDP server; successful code execution has the user's privileges.
The record
- CVE
- CVE-2026-42993
- Published
- Jun 9, 2026
- Updated
- Jun 9, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2025 (Server Core installation)
- Classifications
- CWE-122, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 9, 2026CVE publishedPublication date reported by the CVE source.
- Jun 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.26100.0 <10.0.26100.32995
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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