CVE-2026-39386: Neko has Self-service Privilege Escalation for Authenticated Users
Impact
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.
Patches
The vulnerability has been patched in the following releases:
- v3.0.11 (backport release) - v3.1.2 (latest stable release)
Users should upgrade to v3.0.11 or later (for the 3.0 branch) or v3.1.2 or later.
Workarounds
If upgrading is not immediately possible, the following mitigations can reduce risk:
- Restrict access to trusted users only (avoid granting accounts to untrusted parties) - Run the instance only when needed; avoid leaving it continuously exposed - Disable or restrict access to the /api/profile endpoint if feasible - Monitor for suspicious privilege changes or unexpected administrative actions
Note: These are temporary mitigations and do not fully eliminate the vulnerability. Upgrading is strongly recommended.
Credits Neko thanks @blitzkrieg-patch for responsibly disclosing this vulnerability and reaching out directly. This contribution helped strengthen the project, and the whole community benefits from it.
Other sources
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.
— MITRE
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-39386?
CVE-2026-39386 is considered a high severity vulnerability due to the potential for authenticated users to escalate their privileges to administrative access.
How do I fix CVE-2026-39386?
To fix CVE-2026-39386, update Neko to version 3.0.11 or 3.1.2 or later.
Who is affected by CVE-2026-39386?
CVE-2026-39386 affects Neko versions 3.0.0 through 3.0.10 and 3.1.0 through 3.1.1.
What type of vulnerability is CVE-2026-39386?
CVE-2026-39386 is a self-service privilege escalation vulnerability that allows authenticated users to gain full control over the Neko instance.
Can CVE-2026-39386 be exploited remotely?
Yes, CVE-2026-39386 can be exploited remotely by any authenticated user of the Neko system.