CVE-2026-39386: CWE-20: Improper Input Validation in m1k1o neko
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.
AI Analysis
Technical Summary
The vulnerability identified as 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, effectively compromising the entire instance. The issue has been addressed and patched in versions 3.0.11 and 3.1.2. The CVSS v3.1 score is 8.8, reflecting high impact on confidentiality, integrity, and availability. Temporary mitigations are recommended if upgrading is not immediately feasible, but they do not fully eliminate the risk.
Potential Impact
Successful exploitation allows any authenticated user to gain full administrative privileges on the Neko instance, resulting in complete compromise of the system. This includes unauthorized control over user management, session control, broadcast settings, and other administrative functions, severely impacting confidentiality, integrity, and availability of the service.
Mitigation Recommendations
A fix is available in versions 3.0.11 and 3.1.2 of m1k1o neko and upgrading to these versions is strongly recommended. If immediate upgrade is not possible, temporary mitigations include restricting access to trusted users only, enforcing strong passwords, running the instance only when needed, placing the instance behind additional authentication layers such as a reverse proxy, disabling or restricting access to the /api/profile endpoint if feasible, and monitoring 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
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.
CVSS v3.1
Score 8.8high
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability identified as 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, effectively compromising the entire instance. The issue has been addressed and patched in versions 3.0.11 and 3.1.2. The CVSS v3.1 score is 8.8, reflecting high impact on confidentiality, integrity, and availability. Temporary mitigations are recommended if upgrading is not immediately feasible, but they do not fully eliminate the risk.
Potential Impact
Successful exploitation allows any authenticated user to gain full administrative privileges on the Neko instance, resulting in complete compromise of the system. This includes unauthorized control over user management, session control, broadcast settings, and other administrative functions, severely impacting confidentiality, integrity, and availability of the service.
Mitigation Recommendations
A fix is available in versions 3.0.11 and 3.1.2 of m1k1o neko and upgrading to these versions is strongly recommended. If immediate upgrade is not possible, temporary mitigations include restricting access to trusted users only, enforcing strong passwords, running the instance only when needed, placing the instance behind additional authentication layers such as a reverse proxy, disabling or restricting access to the /api/profile endpoint if feasible, and monitoring 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: 4/28/2026, 5:59:22 AM
Last updated: 6/5/2026, 12:40:55 PM
Views: 95
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