WS-2026-0171
Published:October 19, 2026
Updated:October 22, 2026
OpenCode 1.0.137 through 1.18.32 and 2.0.0 through 2.0.17 pass the OAuth authorization URL returned by a remote MCP server to the 'open' package (10.1.2) without validation. On Windows and WSL, 'open' 10.1.2 embeds the URL unescaped in a PowerShell command, so a malicious or compromised MCP server can execute arbitrary commands when the user starts MCP authentication. Fixed in 1.18.33 and 2.0.18, which restrict the URL to http/https and upgrade 'open' to 11.0.4.
Affected Packages
https://github.com/anomalyco/opencode.git (GITHUB):
Affected version(s) >=v2.0.0 <v2.0.18Fix Suggestion:
Update to version v2.0.18https://github.com/anomalyco/opencode.git (GITHUB):
Affected version(s) >=v1.0.137 <v1.18.33Fix Suggestion:
Update to version v1.18.33Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
8.8
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')