CVEvulnerability

CVE-2026-7839

9.1 CRITICAL Published 2026-07-01 Modified 2026-10-25 Official page ↗
Status
Modified
Published
2026-07-01
Last modified
2026-10-25
Assigner
33c584b5-0579-4c06-b2a0-8d8329fcab9c
CVSS 3.1 (33c584b5-0579-4c06-b2a0-8d8329fcab9c)
9.1 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Weaknesses
CWE-798

Description

UltraVNC repeater through 1.8.2.2 initializes the HTTP administration server with a hardcoded default password. In repeater/webgui/settings.c:197, when settings2.txt is absent on first run the repeater writes the literal string "adminadmi2" as the admin password via strcpy_s(saved_password, 64, "adminadmi2"). The HTTP Basic-auth handler wi_decode_auth() checks this password without rate-limiting or lockout. Any remote attacker who can reach the repeater HTTP port (default TCP 80) can authenticate as administrator using the well-known default credential on a fresh or unmodified installation, gaining full control of the repeater configuration including allow/deny rules and session visibility.

Affected configurations

• uvnc ultravnc (<= 1.8.2.2)

Related

Weakness · CWE (1)

  • CWE-798 Use of Hard-coded Credentials weakness

References