What is CVE-2026-7830?

CVE-2026-7830 is a high-severity vulnerability in Uvnc Ultravnc, classified under Inadequate Encryption Strength. CVSS score: 7.4/10. Published 2026-07-01.

How severe is CVE-2026-7830?

High severity. CVSS v3 base score is 7.4 out of 10.

Vulnerability in Uvnc Ultravnc

CVE-2026-7830

UltraVNC through 1.8.2.2 uses inadequate cryptography in the MS-Logon II authentication scheme (rfbUltraVNC_MsLogonIIAuth). In rfb/dh.cpp the Diffie-Hellman key exchange is performed with parameters that fit in an unsigned 64-bit integer (…

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Uvnc Ultravnc — versions 0

Weakness classification (CWE)

CWE-326 — Inadequate Encryption Strength
CWE-338 — Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

References

33c584b5-0579-4c06-b2a0-8d8329fcab9c (vendor-advisory)
33c584b5-0579-4c06-b2a0-8d8329fcab9c (product)

Frequently asked questions

What is CVE-2026-7830?: CVE-2026-7830 is a high-severity vulnerability in Uvnc Ultravnc, classified under Inadequate Encryption Strength. CVSS score: 7.4/10. Published 2026-07-01.
How severe is CVE-2026-7830?: High severity. CVSS v3 base score is 7.4 out of 10.