CVE-2026-39386

HIGH CVSS 3.1: 8.8 EPSS 0.44%
Updated Oct 27, 2026
M1K1O
Parameter Value
CVSS 8.8 (HIGH)
Affected Versions 3.0.0 — 3.1.2
Fixed In 3.0.11
Type CWE-862 (Missing Authorization), CWE-269 (Improper Privilege Management), CWE-20 (Improper Input Validation), CWE-284 (Improper Access Control), CWE-639 (Authorization Bypass)
Vendor M1K1O
Public PoC No

Neko is a a self-hosted virtual browser that runs in Docker and uses WebRTC In versions 3.0.0 through 3.0.10 and 3.1.0 through 3.1.1, any authenticated user can immediately obtain full administrative control of the entire Neko instance (member management, room settings, broadcast control, session termination, etc.). This results in a complete compromise of the instance. The vulnerability has been patched in v3.0.11 and v3.1.2.

If upgrading is not immediately possible, the following mitigations can reduce risk: Restrict access to trusted users only (avoid granting accounts to untrusted parties); ensure all user passwords are strong and only shared with trusted individuals; run the instance only when needed; avoid leaving it continuously exposed; place the instance behind authentication layers such as a reverse proxy with additional access controls; disable or restrict access to the /api/profile endpoint if feasible; and/or monitor for suspicious privilege changes or unexpected administrative actions. Note that these are temporary mitigations and do not fully eliminate the vulnerability. Upgrading is strongly recommended.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service

CVSS Vector v3.1

Vulnerable Products 2

Configuration From (including) Up to (excluding)
M1k1o Neko
cpe:2.3:a:m1k1o:neko:*:*:*:*:*:*:*:*
3.0.0 3.0.11
M1k1o Neko
cpe:2.3:a:m1k1o:neko:*:*:*:*:*:*:*:*
3.1.0 3.1.2

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