MEDIUMCVSS v4 6.9Vulnerability
CVE-2026-65957
Helio is an MCP proxy that sits between AI agents and the tools they use. Prior to version 0.8.0, the dashboard sideband (default 127.0.0.1:3100) validated CORS request origins by matching the hostname against a private-network string prefix (10., 172.16.–172.31., 192.168.) rather than validating an IP address. A public DNS name such as 192.168.attacker.com, 10.evil.io, or 172.16.pwn.example also satisfies that prefix, so the proxy echoed the attacker origin in Access-Control-Allow-Origin. This issue has been patched in version 0.8.0.
Properties
- Severity
- MEDIUM
- Nvd fetched at
- 2026-11-11T23:49:45.533241+00:00
- Cvss score
- 6.9
- Cvss severity
- MEDIUM
- Retrieved at
- 2026-11-11T23:50:18+00:00
- Score
- 6.9
- Last source
- NVD
- Cvss version
- 4.0
- Cve id
- CVE-2026-65957
- Cvss vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- First seen by Signal
- 2026-11-11T23:46:41+00:00
- Name
- CVE-2026-65957
- Vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Published at
- 2026-11-11T21:16:46.243
- Last modified
- 2026-11-11T21:16:46.243
Related Entities (2)
HAS_WEAKNESS (2)
Related research
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