CVE-2026-7839
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure, data tampering.
- Exploit odds
- 0.7% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.7% in the next 30 days (EPSS).
- Severity: 9.1 CRITICAL (CVSS).
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 0.7% · EPSS, next 30 days
- Weakness
- CWE-798 · Hard-coded credentials
- Record status
- Modified
Affected
- Uvnc Ultravnc ≤ 1.8.2.2
Attack profile CVSS 3.1 · 9.1
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-7839.md and follow it. Check whether this project is affected by CVE-2026-7839. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
