CVE-2026-5029
RCE in Code Runner MCP Server
- State
- Published
- Severity
- 8.7 High
- Published
- May 12, 2026
- Updated
- May 12, 2026
- Reserved
- Mar 27, 2026
Description
A remote code execution vulnerability exists in Code Runner MCP Server when run with the --transport http option, which exposes the /mcp JSON-RPC endpoint without authentication on port 3088. An unauthenticated remote attacker can invoke the run-code MCP tool to supply arbitrary source code and execute it via child_process.exec() using the specified language interpreter. This allows execution of arbitrary code with the privileges of the user running the server. This vulnerability has not been fixed and might affect the project in all versions.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.7 High | CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | CERT-PL |
Weaknesses
- CWE-306 Missing Authentication for Critical Function
Affected Products
| Product | Versions |
|---|---|
Code Runner MCP ServerCode Runner MCP Server |
|
References
- https://cert.pl/en/posts/2026/05/CVE-2026-5029third-party-advisory
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