CVE-2026-39386CWE-20CWE-269CWE-284CWE-639CWE-862

Neko has Self-service Privilege Escalation for Authenticated Users

High · published April 21, 2026

CVSS v3.1
8.8
EPSS
1%
Percentile
50.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.8 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00639 · 50.0th percentile
Weaknesses
CWE-20 · Improper Input Validation; CWE-269 · Improper Privilege Management; CWE-284 · Improper Access Control; CWE-639 · Authorization Bypass Through User-Controlled Key; CWE-862 · Missing Authorization
Published
2026-04-21T00:50Z
EPSS history
Timeline
  • 21 APR 00:50Z
    Neko has Self-service Privilege Escalation for Authenticated Users
    cvelistv5