Critical Vulnerability in RustDesk Windows Clipboard Redirection

Severity

CRITICAL

CVSS

9.6

Affected component

rustdesk (cargo)

Affected versions

>= 3.5.1, <= 3.5.1 or >= 3.5.0, <= 3.5.0 or >= 3.4.0, <= 3.4.0 or >= 3.3.0, <= 3.3.0 or >= 3.2.0, <= 3.2.0 or >= 3.1.0, <= 3.1.0 or >= 3.0.0, <= 3.0.0 or >= 3.0.0-rc0, <= 3.0.0-rc0 or >= 3.0.0-beta4, <= 3.0.0-beta4 or >= 3.0.0-beta3, <= 3.0.0-beta3 or >= 3.0.0-beta2, <= 3.0.0-beta2 or >= 3.0.0-beta1, <= 3.0.0-beta1 or >= 2.0.0, <= 2.0.0 or >= 2.0.0-rc4, <= 2.0.0-rc4 or >= 2.0.0-rc3, <= 2.0.0-rc3 or >= 2.0.0-rc2, <= 2.0.0-rc2 or >= 2.0.0-rc1, <= 2.0.0-rc1 or >= 2.0.0-rc0, <= 2.0.0-rc0 or >= 2.0.0-beta1+android11, <= 2.0.0-beta1+android11 or >= 2.0.0-beta1+android10, <= 2.0.0-beta1+android10 or >= 1.2.0-beta1+android9, <= 1.2.0-beta1+android9 or >= 1.2.0-beta1+android7, <= 1.2.0-beta1+android7 or >= 1.1.0-beta+2013071101, <= 1.1.0-beta+2013071101 or >= 1.1.0-beta1+ios4, <= 1.1.0-beta1+ios4 or >= 1.1.0-beta1+android5, <= 1.1.0-beta1+android5 or >= 1.1.0-beta1+android4, <= 1.1.0-beta1+android4 or >= 1.1.0-beta1+ios3, <= 1.1.0-beta1+ios3 or >= 1.1.0-beta1+ios2, <= 1.1.0-beta1+ios2 or >= 1.1.0-beta1+android3, <= 1.1.0-beta1+android3 or >= 1.1.0-beta1+android2, <= 1.1.0-beta1+android2 or >= 1.1.0-beta1+ios1, <= 1.1.0-beta1+ios1 or >= 1.1.0-beta1, <= 1.1.0-beta1 or >= 1.0.1, <= 1.0.1 or >= 1.0.0, <= 1.0.0 or >= 1.0-beta5, <= 1.0-beta5 or >= 1.0-beta4, <= 1.0-beta4 or >= 1.0-beta2, <= 1.0-beta2 or >= 1.0-beta1, <= 1.0-beta1

Patched version

Not yet available

An early warning has been issued for a critical vulnerability in RustDesk's Windows clipboard redirection feature, which could allow a malicious peer to write attacker-chosen data past the end of a buffer.

What happened

An early warning has been issued for a critical vulnerability in RustDesk's Windows clipboard redirection feature. This vulnerability, tracked as CVE-2026-76840 and CVE-2026-68579, allows a malicious peer to write attacker-chosen data past the end of a fixed-size buffer due to a lack of an upper bound check. This issue affects all versions of RustDesk that use the clipboard redirection feature, from version 1.0-beta1 up to and including version 3.5.1.

The vulnerability arises when RustDesk's clipboard redirection copies a peer-supplied length into a fixed-size buffer without verifying that the length does not exceed the buffer's size. This can lead to a buffer overflow, potentially allowing an attacker to execute arbitrary code or cause a denial of service.

This vulnerability has not been reported as exploited in the wild. However, given its severity and the potential for remote code execution, it is critical that users assess their exposure and take appropriate mitigation steps.

What to do about it

• Check the version of RustDesk currently in use to determine if it is affected by this vulnerability.
• If using an affected version, upgrade to the latest version of RustDesk that includes the fix for this vulnerability.
• Monitor the primary sources for updates on this vulnerability and any additional mitigation steps that may be recommended.
• Consider disabling the clipboard redirection feature in RustDesk until the vulnerability is patched if an upgrade is not immediately possible.
• Review the security practices and configurations of any systems that use RustDesk to ensure they are not exposed to potential exploitation of this vulnerability.

How 0Day would have caught this

Read how this differs from waiting on a scanner to catch a known advisory, or see the exact, read-only access 0Day needs to do this for an organization.

Frequently asked questions

Sources

• [CVE-2026-76840] CVSS 9.6 CRITICAL

Join the 0Day waitlist →

← Back to all threats