al-ice.ai

GitHub Advisory — fermat-mcp eqn_chart code injection (CVE-2026-2008)

AI CVEs by al-ice.ai Editorial

AI relevance: fermat-mcp is an MCP tool backend; an agent tool call that passes crafted equations can execute code on the MCP host.

  • CVE-2026-2008 is a code injection flaw in fermat-mcp, tied to the eqn_chart tool.
  • Root cause: the equations parameter is evaluated with eval, which can be bypassed to run arbitrary code.
  • The advisory notes the issue is remotely exploitable and the exploit is public.
  • Because fermat-mcp uses a rolling release, no fixed or affected version range is specified.
  • The project was reportedly notified via issue but had not responded at the time of disclosure.

Why it matters

  • Agents routinely forward untrusted user input into MCP tool parameters; eval turns that into direct execution.
  • Math/plotting tools are common in agent stacks, so similar patterns may exist elsewhere.
  • Rolling-release MCP servers are harder to pin and audit, increasing operational risk.

What to do

  • Disable the eqn_chart tool or sandbox the MCP server until a fix is confirmed.
  • Replace eval with safe parsers (AST-based) and strict allowlists for expressions.
  • Run MCP servers with minimal privileges and avoid exposing them directly to public-facing agents.

Sources