Vulnerability · Published Mar 5, 2026 · Assigned by VULSec

CVE-2026-30796RustDesk Client Transmits Preset Address Book Password Verbatim in Heartbeat Sync

Medium 6.9

In plain English

A medium-severity security flaw in RustDesk Client from rustdesk-client. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).

Severity (CVSS 4.0)6.9Medium

Exploit odds (30 days)0.5%top 59.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Cleartext Transmission of Sensitive Information, Insufficiently Protected Credentials vulnerability in rustdesk-client RustDesk Client rustdesk-client on Windows, MacOS, Linux, iOS, Android (Address book sync, Heartbeat sync loop modules) allows Sniffing Attacks. The client places the preset address-book password verbatim into the heartbeat sync JSON body (src/hbbs_http/sync.rs). Over an intact HTTPS session it is not exposed in transit, but it is a reusable shared secret rather than a zero-knowledge proof, so it is recovered by any party that becomes the API endpoint - under the re-homed/rogue API server (CVE-2026-30797) - and the leaked credential then authorizes the server-side address book. This vulnerability is associated with program files src/hbbs_http/sync.rs and program routines heartbeat sync body builder (emits preset-address-book-password). This issue affects RustDesk Client: through 1.4.8.

Affected products (as reported)

Vendor	Product	Versions
rustdesk-client	RustDesk Client	0 – through 1.4.8

Weakness: CWE-522 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N

References

https://rustdesk.com/docs/en/ technical-description, x_--config documentation
https://docs.google.com/document/d/e/2PACX-1vSds6jjpd38oO_yIAyd1HYtKNUuea-I-ozAPpGhYI7QgAU-QGJ7D8a4rOZVj1vmiUXV1EcdRHf9aZAW/pub third-party-advisory, exploit
https://www.vulsec.org/ vdb-entry, third-party-advisory