Threat
OpenCode Flaw Lets Malicious MCP Servers Execute Code During Sign-In on Windows and WSL
First reported thehackernews.com
Page published
Earliest dated coverage: 22 Oct 2026 · First observed: 22 Oct 2026 · Latest dated coverage: 22 Oct 2026
Coverage timeline
Single-source incident — one report is available.
Why it matters
OpenCode users on Windows and WSL should upgrade to version 1.18.33 or later because MCP authentication could trigger code execution, and the reported absence of a CVE leaves vulnerable builds unflagged by vulnerability scanners.
OpenCode versions 1.0.137 through 1.18.32 allowed a malicious or compromised MCP server to execute PowerShell commands during sign-in on Windows and WSL. The browser-opening helper failed to escape the server-supplied OAuth authorization endpoint, allowing commands to run with the developer's privileges. Anomaly fixed the flaw in version 1.18.33 without requesting a CVE or publishing a security advisory.