CVE-2026-30790 HIGH

CVE-2026-30790: RustDesk Login Proof Exposed in Cleartext on the Server Pro /api Channel Under TLS Downgrade

Vendor Rustdesk-Client
Product RustDesk Client
Weakness CWE-916
Published March 5, 2026
Last update June 22, 2026

CVSS base score

8.2/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Use of Password Hash With Insufficient Computational Effort, Cleartext Transmission of Sensitive Information vulnerability in rustdesk-client RustDesk Client rustdesk-client on Windows, MacOS, Linux, iOS, Android (Server Pro /api login over the HTTP management channel) allows Interception (aka Sniffing) followed by offline Password Brute Forcing. The controlled-host peer authentication channel is NOT affected: Client::secure_connection verifies the HBBS-signed host public key and negotiates an XSalsa20-Poly1305 secretbox session before the login proof is sent, so passive capture and relay man-in-the-middle do not expose it (capture-replay / CWE-294 withdrawn). On the Server Pro /api login path the proof is protected by TLS alone, is exposed under the automatic invalid-certificate downgrade (CVE-2026-30794), and is recoverable offline because it is a fast double SHA256 over a server-controlled salt and challenge with no slow KDF. This vulnerability is associated with program files src/client.rs and src/common.rs and program routines handle_hash(), handle_login_from_ui() (login proof construction) and post_request_() (API transport). This issue affects RustDesk Client: through 1.4.8.

Key dates

02Disclosure timeline

March 5, 2026 CVE published
June 22, 2026 Record updated