CVE-2026-39386: CWE-20: Improper Input Validation in m1k1o neko
CVE-2026-39386 is a high-severity vulnerability in m1k1o neko, a self-hosted virtual browser running in Docker using WebRTC. In versions 3. 0. 0 through 3. 0. 10 and 3. 1. 0 through 3. 1. 1, any authenticated user can gain full administrative control over the entire instance, including member management, room settings, broadcast control, and session termination.
AI Analysis
Technical Summary
The vulnerability CVE-2026-39386 affects m1k1o neko versions 3.0.0 to 3.0.10 and 3.1.0 to 3.1.1. It stems from improper input validation (CWE-20) that allows any authenticated user to escalate privileges immediately to full administrative control of the instance. This includes control over member management, room settings, broadcast control, and session termination, resulting in complete compromise. The issue is addressed by patches in versions 3.0.11 and 3.1.2. Temporary mitigations can reduce risk but do not fully eliminate the vulnerability.
Potential Impact
An authenticated user can fully compromise the Neko instance by gaining administrative privileges, allowing them to manage users, modify room settings, control broadcasts, and terminate sessions. This results in complete loss of confidentiality, integrity, and availability of the instance.
Mitigation Recommendations
A fix is available in m1k1o neko versions 3.0.11 and 3.1.2; upgrading to these versions is strongly recommended. If immediate upgrade is not possible, apply temporary mitigations: restrict access to trusted users only, enforce strong passwords, run the instance only when needed, place it behind additional authentication layers such as a reverse proxy, disable or restrict access to the /api/profile endpoint if feasible, and monitor for suspicious administrative actions. These mitigations reduce risk but do not fully resolve the vulnerability.
CVE-2026-39386: CWE-20: Improper Input Validation in m1k1o neko
Description
CVE-2026-39386 is a high-severity vulnerability in m1k1o neko, a self-hosted virtual browser running in Docker using WebRTC. In versions 3. 0. 0 through 3. 0. 10 and 3. 1. 0 through 3. 1. 1, any authenticated user can gain full administrative control over the entire instance, including member management, room settings, broadcast control, and session termination.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-39386 affects m1k1o neko versions 3.0.0 to 3.0.10 and 3.1.0 to 3.1.1. It stems from improper input validation (CWE-20) that allows any authenticated user to escalate privileges immediately to full administrative control of the instance. This includes control over member management, room settings, broadcast control, and session termination, resulting in complete compromise. The issue is addressed by patches in versions 3.0.11 and 3.1.2. Temporary mitigations can reduce risk but do not fully eliminate the vulnerability.
Potential Impact
An authenticated user can fully compromise the Neko instance by gaining administrative privileges, allowing them to manage users, modify room settings, control broadcasts, and terminate sessions. This results in complete loss of confidentiality, integrity, and availability of the instance.
Mitigation Recommendations
A fix is available in m1k1o neko versions 3.0.11 and 3.1.2; upgrading to these versions is strongly recommended. If immediate upgrade is not possible, apply temporary mitigations: restrict access to trusted users only, enforce strong passwords, run the instance only when needed, place it behind additional authentication layers such as a reverse proxy, disable or restrict access to the /api/profile endpoint if feasible, and monitor for suspicious administrative actions. These mitigations reduce risk but do not fully resolve the vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-06T22:06:40.515Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69e70c3119fe3cd2cda19916
Added to database: 4/21/2026, 5:33:37 AM
Last enriched: 4/21/2026, 5:33:59 AM
Last updated: 4/21/2026, 7:46:27 AM
Views: 7
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