{"apiVersion":"1.0","identifier":"CVE-2026-76840","description":"RustDesk-s Windows clipboard redirection copies a peer-supplied length into a fixed-size caller buffer without an upper bound check. When an OLE paste consumer such as explorer.exe calls IStream::Read with a buffer of cb bytes, CliprdrStream_Read in libs/clipboard/src/windows/wf_cliprdr.c requests that many bytes of a remote file through cliprdr_send_request_filecontents and then executes CopyMemory(pv, clipboard->req_fdata, clipboard->req_fsize), where req_fsize is taken verbatim from the peer-s CLIPRDR FileContentsResponse by wf_cliprdr_server_file_contents_response (req_fsize = fileContentsResponse->cbRequested) and is never clamped to cb anywhere in the chain. The function-s only length comparison, req_fsize < cb, handles the short-read case and is evaluated after the copy has already occurred. A malicious or compromised peer that answers a small file-contents read with an oversized response therefore writes attacker-chosen data past the end of the paste consumer-s heap buffer when the local user pastes clipboard file contents offered by the remote side. The file is a fork of FreeRDP-s client/Windows/wf_cliprdr.c, where the same defect is CVE-2026-68579, fixed in FreeRDP 3.30.0.","publishedAt":"2026-08-24T14:17:01","lastModifiedAt":"2026-08-24T17:18:17","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-76840","cvssScore":9.6,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:H","epssProbability":0.003,"riskScore":0.99,"affectedProduct":"RustDesk","affectedVersions":"unknown","vulnerabilityType":"Other","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-76840","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-76840","en":"https://www.redsauce.net/en/cves/CVE-2026-76840","fr":"https://www.redsauce.net/fr/cves/CVE-2026-76840","pt":"https://www.redsauce.net/pt/cves/CVE-2026-76840","de":"https://www.redsauce.net/de/cves/CVE-2026-76840","sk":"https://www.redsauce.net/sk/cves/CVE-2026-76840","el":"https://www.redsauce.net/el/cves/CVE-2026-76840"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-76840"}}