Update merge request fields.
AI agents use gitlab_update_merge_request to create or update resources in Gitlab — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Gitlab environment.
This tool creates or modifies data reversibly without deletion, matching the Write category definition. Severity is high because merge requests are critical control points in software development pipelines; malicious updates could redirect code reviews, remove approvals, reassign reviewers, or alter merge conditions, potentially allowing unauthorized code to reach production.
From the tool's definition Tool description states 'Update merge request fields' which modifies existing merge request data. The sibling tools include merge request management operations like gitlab_approve_merge_request and gitlab_create_draft_note, indicating this server manages code…
Documented attack patterns abuse exactly the kind of access gitlab_update_merge_request gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Gitlab, and nothing reaches the server without passing your rules. This is the rule we recommend for gitlab_update_merge_request:
{
"version": "1",
"default": "deny",
"tools": {
"gitlab_update_merge_request": {
"limits": [
{
"counter": "gitlab_update_merge_request_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}gitlab_update_merge_request stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Update merge request fields. It is categorised as a Write tool in the Gitlab MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Gitlab MCP server in PolicyLayer and add a rule for gitlab_update_merge_request: 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 Gitlab. Nothing to install.
gitlab_update_merge_request is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the gitlab_update_merge_request 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.
Set action: deny in the PolicyLayer policy for gitlab_update_merge_request. 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.
gitlab_update_merge_request is provided by the Gitlab MCP server (mcpland/gitlab-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Gitlab, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
190 Gitlab tools catalogued and risk-classified — across an index of 43,000+ MCP servers.