jenkins_replay_build · Mcp Jenkins MCP: Risk & Policy

WHAT IT DOES

What jenkins_replay_build does on Mcp Jenkins

AI agents invoke jenkins_replay_build to trigger actions in Mcp Jenkins. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why jenkins_replay_build needs a policy

This tool triggers execution of CI/CD pipeline scripts whose behavior depends on user input (the optional 'modified pipeline script'). Even without modification, replaying a build re-executes code on Jenkins agents, which could deploy malicious code, access secrets, modify infrastructure, or trigger downstream operations. The ability to modify the script makes this particularly dangerous.

From the tool's definition Tool description states it will 'Replay/rerun a pipeline build, optionally with a modified pipeline script' — this executes arbitrary pipeline code on Jenkins infrastructure, potentially with attacker-controlled modifications.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

jenkins_replay_build Rate-limited

jenkins_replay_build stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "jenkins_replay_build": {
      "limits": [
        {
          "counter": "jenkins_replay_build_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Mcp Jenkins, so you can run agents against it safely.

FAQ

Questions about jenkins_replay_build

What does the jenkins_replay_build tool do? +

Replay/rerun a pipeline build, optionally with a modified pipeline script. It is categorised as a Execute tool in the Mcp Jenkins MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on jenkins_replay_build? +

Register the Mcp Jenkins MCP server in PolicyLayer and add a rule for jenkins_replay_build: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Mcp Jenkins. Nothing to install.

What risk level is jenkins_replay_build? +

jenkins_replay_build is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit jenkins_replay_build? +

Yes. Add a rate_limit block to the jenkins_replay_build rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block jenkins_replay_build completely? +

Set action: deny in the PolicyLayer policy for jenkins_replay_build. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides jenkins_replay_build? +

jenkins_replay_build is provided by the Mcp Jenkins MCP server (@kud/mcp-jenkins). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.