Heap overwrite via unbounded clipboard response length
Published Aug 24, 2026 · Updated Aug 24, 2026
Heap buffer overflow in RustDesk 1.4.9 and earlier allows remote attackers to overwrite heap memory via clipboard file data. CliprdrStream_Read copies req_fsize bytes from a peer-controlled FileContentsResponse into the paste consumer's cb-byte buffer without clamping the copy to cb. Exploitation requires a malicious or compromised remote peer and a local user paste, and it corrupts heap memory in an OLE consumer such as explorer.exe.
Summary
What happened
Heap buffer overflow in RustDesk 1.4.9 and earlier allows remote attackers to overwrite heap memory via clipboard file data. CliprdrStream_Read copies req_fsize bytes from a peer-controlled FileContentsResponse into the paste consumer's cb-byte buffer without clamping the copy to cb. Exploitation requires a malicious or compromised remote peer and a local user paste, and it corrupts heap memory in an OLE consumer such as explorer.exe.
The record
- CVE
- CVE-2026-76840
- Published
- Aug 24, 2026
- Updated
- Aug 24, 2026
- Vendor
- RustDesk
- Product
- RustDesk
- Classifications
- CWE-787, T1203
- Attack vector
- network
- Privileges
- Unavailable
Timeline
How it unfolded
- Aug 24, 2026CVE publishedPublication date reported by the CVE source.
- Aug 24, 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=0 <=1.4.9
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.
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Technologies
Your stack
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Your stack
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