{"id":"CVE-2026-7839","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-7839","summary":"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…","details":"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.","published":"2026-07-01T05:16:24.680","modified":"2026-07-09T06:16:22.213","cvss":{"score":9.1,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[],"fix":null,"references":[{"type":"WEB","url":"https://github.com/ultravnc/UltraVNC"},{"type":"WEB","url":"https://uvnc.com/"},{"type":"WEB","url":"https://www.securin.io/zero-days/cve-2026-7839-hardcoded-default-admin-password-adminadmi2-ultravnc-repeater"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T06:16:22.213"}}