What’s Vulnerable › Vulnerabilities

CVE-2026-68579: FreeRDP before 3.30.0 Heap Overflow via CliprdrStream_Read

• Severity: critical (CVSS 9.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-02 · updated 2026-09-29
• Weakness: CWE-787

Description

FreeRDP before 3.30.0 (<= 3.29.0) contains a heap-based buffer overflow in the Windows clipboard client's CliprdrStream_Read function (client/Windows/wf_cliprdr.c). When an OLE paste consumer (e.g. explorer.exe) calls IStream::Read with a fixed-size buffer of cb bytes, CliprdrStream_Read requests file contents from the RDP server and then copies the response into the caller's buffer using the server-supplied length (req_fsize) instead of cb. A malicious or compromised RDP server can return an oversized CB_FILECONTENTS_RESPONSE, causing an out-of-bounds write of attacker-controlled data into the paste consumer's heap buffer when a user pastes server-offered clipboard file contents.

Affected products

• FreeRDP: before 3.30.0 — fixed in 3.30.0

How to fix

Upgrade to a fixed version: FreeRDP 3.30.0. Check the vendor advisory for mitigations.

References

• https://github.com/FreeRDP/FreeRDP/commit/5e8e987b469b60a3bafadf8f5afc40f91c09f458
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-m37j-jcr2-8gcc
• https://www.vulncheck.com/advisories/freerdp-before-heap-overflow-via-cliprdrstream-read

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