Vulnerability Description
Use of Password Hash With Insufficient Computational Effort, Improper Restriction of Excessive Authentication Attempts vulnerability in rustdesk-client RustDesk Client rustdesk-client on Windows, MacOS, Linux, iOS, Android (Client login, peer authentication modules) allows Password Brute Forcing. The authentication proof is SHA256(SHA256(password + salt) + challenge), where both the salt and the challenge are generated entirely by the server with no client-side nonce, and the hash uses no slow key-derivation function. A rogue or on-path API/relay server (see CVE-2026-30794 / CVE-2026-30797) can issue a chosen salt and challenge, capture the resulting proof, and recover the password offline. The capture-replay claim (CWE-294) is withdrawn: the challenge is regenerated per connection (challenge = Config::get_auto_password(6)), so a captured proof is not replayable against the legitimate server. The 1.4.7 OTP brute-force limiter and the existing LOGIN_FAILURES counter constrain only ONLINE attempts and do not address offline recovery. This vulnerability is associated with program files src/client.rs and program routines handle_hash(), handle_login_from_ui() (login proof construction). This issue affects RustDesk Client: through 1.4.8.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Rustdesk | Rustdesk | <= 1.4.5 |
| Apple | Iphone Os | - |
| Apple | Macos | - |
| Android | - | |
| Linux | Linux Kernel | - |
| Microsoft | Windows | - |
Related Weaknesses (CWE)
References
- https://docs.google.com/document/d/e/2PACX-1vSds6jjpd38oO_yIAyd1HYtKNUuea-I-ozAPExploitThird Party Advisory
- https://rustdesk.com/docs/en/client/Product
- https://www.vulsec.org/Not Applicable
FAQ
What is CVE-2026-30789?
CVE-2026-30789 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Use of Password Hash With Insufficient Computational Effort, Improper Restriction of Excessive Authentication Attempts vulnerability in rustdesk-client RustDesk Client rustdesk-client on Windows, MacO...
How severe is CVE-2026-30789?
CVE-2026-30789 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-30789?
Check the references section above for vendor advisories and patch information. Affected products include: Rustdesk Rustdesk, Apple Iphone Os, Apple Macos, Google Android, Linux Linux Kernel.