CVE-2026-5029CWE-306

RCE in Code Runner MCP Server

High · published May 12, 2026

CVSS v4.0
8.7
EPSS
0%
Percentile
37.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
8.7 · HIGH
Vector
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
EPSS
0.00437 · 37.0th percentile
Weakness
CWE-306 · Missing Authentication for Critical Function
Published
2026-05-12T09:01Z
EPSS history
Timeline
  • 12 MAY 09:01Z
    RCE in Code Runner MCP Server
    cvelistv5