{"id":"CVE-2026-7839","aliases":["EUVD-2026-40885","GHSA-h7cc-6wq3-9h7x"],"status":"published","title":"UltraVNC repeater ships hardcoded default admin password allowing unauthenticated admin access","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.","severity":{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00655,"percentile":0.51721,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-798"],"published":"2026-07-01T03:33:27Z","modified":"2026-10-25T17:10:00Z","products":[{"vendor":"uvnc","product":"ultravnc"}],"references":[{"url":"https://uvnc.com/","tags":["vendor-advisory","Product","Release Notes"]},{"url":"https://github.com/ultravnc/UltraVNC","tags":["product","Product"]},{"url":"https://www.securin.io/zero-days/cve-2026-7839-hardcoded-default-admin-password-adminadmi2-ultravnc-repeater"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-7839"},{"url":"https://uvnc.com"},{"url":"https://github.com/advisories/GHSA-h7cc-6wq3-9h7x"}],"sources":{"cve":[{"id":"CVE-2026-7839","title":"UltraVNC repeater ships hardcoded default admin password allowing unauthenticated admin access","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.","status":"published","published":"2026-07-01T03:33:27.724Z","modified":"2026-07-09T04:35:44.027Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical","assessor":"cna"}],"cwes":["CWE-798"],"updated_at":"2026-11-02T14:20:05.830416Z"}],"euvd":[{"id":"EUVD-2026-40885","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.","status":"published","published":"2026-07-01T03:33:27Z","modified":"2026-07-09T04:35:44Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical"}],"updated_at":"2026-11-02T18:20:04.895477Z"}],"ghsa":[{"id":"GHSA-h7cc-6wq3-9h7x","title":"UltraVNC repeater through 1.8.2.2 initializes the HTTP administration server with a hardcoded...","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.","status":"published","published":"2026-07-01T06:31:34Z","modified":"2026-07-09T06:33:00Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical"}],"cwes":["CWE-798"],"updated_at":"2026-11-02T15:09:20.981798Z"}],"nvd":[{"id":"CVE-2026-7839","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.","status":"published","published":"2026-07-01T05:16:24.68Z","modified":"2026-10-25T17:10:00.197Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical","assessor":"secondary"}],"cwes":["CWE-798"],"updated_at":"2026-11-02T14:12:27.199837Z"}]}}