Neko has Self-service Privilege Escalation for Authenticated Users
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Privilege escalation, Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-269 and CWE-284.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| m1k1o | neko | 3.0.0 to before 3.0.11; 3.1.0 to before 3.1.2 | 3.0.11, 3.1.2 | Patch available | CNA |
| — | github.com/m1k1o/neko/server (Go) | 3.0.0 to before 3.0.11 | 3.0.11 | Patch available | GHSA-2gw9-c2r2-f5qf |
| — | github.com/m1k1o/neko/server (Go) | 0.0.0-20250322225643-212bf8a60756 to before 0.0.0-20260406184107-c54bcf1ee211 | 0.0.0-20260406184107-c54bcf1ee211 | Patch available | GHSA-2gw9-c2r2-f5qf |
- neko Vendorm1k1o Affected 3.0.0 to before 3.0.11; 3.1.0 to before 3.1.2 Fixed in 3.0.11, 3.1.2 Patch available CNA
- github.com/m1k1o/neko/server (Go) Vendor— Affected 3.0.0 to before 3.0.11 Fixed in 3.0.11 Patch available GHSA-2gw9-c2r2-f5qf
- github.com/m1k1o/neko/server (Go) Vendor— Affected 0.0.0-20250322225643-212bf8a60756 to before 0.0.0-20260406184107-c54bcf1ee211 Fixed in 0.0.0-20260406184107-c54bcf1ee211 Patch available GHSA-2gw9-c2r2-f5qf
Remediation
- Fix · CNA neko (m1k1o) Fixed in 3.0.11, 3.1.2
- Fix · GHSA-2gw9-c2r2-f5qf github.com/m1k1o/neko/server (Go) Fixed in 3.0.11 Advisory →
- Fix · GHSA-2gw9-c2r2-f5qf github.com/m1k1o/neko/server (Go) Fixed in 0.0.0-20260406184107-c54bcf1ee211 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-39386
- 2026-10-03 Alias added: GHSA-2gw9-c2r2-f5qf
- 2026-10-24 EPSS moved to the 50th–90th percentile
- 2026-10-25 EPSS moved to the below the 50th percentile
References
Advisory 2
Sources
- CVE-2026-39386 · CVE Program
- CVE-2026-39386 · NVD
- FIRST EPSS
- GHSA-2gw9-c2r2-f5qf · GitHub Advisory Database · CC BY 4.0
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