{"cve":"CVE-2026-7839","nvd":{"published":"2026-07-01T05:16:24.680","modified":"2026-10-25T17:10:00.197","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","score":9.1},"cwes":["CWE-798"],"references":["https://github.com/ultravnc/UltraVNC","https://uvnc.com/","https://www.securin.io/zero-days/cve-2026-7839-hardcoded-default-admin-password-adminadmi2-ultravnc-repeater"],"products":["uvnc:ultravnc"],"source":"nvd","synced_at":"2026-10-25T17:50:06.907763985+00:00"},"epss":{"cve":"CVE-2026-7839","score":0.00655,"percentile":0.51087,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}