{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-7839: UltraVNC repeater ships hardcoded default admin password allowing unauthenticated admin access","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-7839","status":"final","version":"1","initial_release_date":"2026-07-01T03:33:27.724Z","current_release_date":"2026-07-01T03:33:27.724Z","revision_history":[{"date":"2026-07-01T03:33:27.724Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"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.","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-7839 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-7839"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-7839"},{"category":"external","summary":"UltraVNC project page","url":"https://uvnc.com/"},{"category":"external","summary":"UltraVNC source repository","url":"https://github.com/ultravnc/UltraVNC"}]},"product_tree":{"branches":[{"category":"vendor","name":"uvnc","branches":[{"category":"product_name","name":"UltraVNC","branches":[{"category":"product_version_range","name":"<=1.8.2.2","product":{"name":"uvnc UltraVNC <=1.8.2.2","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:uvnc:ultravnc:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-7839","title":"UltraVNC repeater ships hardcoded default admin password allowing unauthenticated admin access","notes":[{"category":"description","text":"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.","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1"]},"scores":[{"cvss_v3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","baseScore":9.1,"baseSeverity":"CRITICAL"},"products":["CSAFPID-1"]}],"remediations":[{"category":"none_available","details":"No fixed version is published yet. Monitor the upstream advisory.","product_ids":["CSAFPID-1"]}]}]}